1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP__HASH_TABLE
11#define _LIBCPP__HASH_TABLE
12
13#include <__config>
14#include <initializer_list>
15#include <memory>
16#include <iterator>
17#include <algorithm>
18#include <cmath>
19#include <utility>
20#include <type_traits>
21
22#include <__debug>
23
24#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
25#pragma GCC system_header
26#endif
27
28_LIBCPP_PUSH_MACROS
29#include <__undef_macros>
30
31
32_LIBCPP_BEGIN_NAMESPACE_STD
33
34template <class _Key, class _Tp>
35struct __hash_value_type;
36
37#ifndef _LIBCPP_CXX03_LANG
38template <class _Tp>
39struct __is_hash_value_type_imp : false_type {};
40
41template <class _Key, class _Value>
42struct __is_hash_value_type_imp<__hash_value_type<_Key, _Value>> : true_type {};
43
44template <class ..._Args>
45struct __is_hash_value_type : false_type {};
46
47template <class _One>
48struct __is_hash_value_type<_One> : __is_hash_value_type_imp<typename __uncvref<_One>::type> {};
49#endif
50
51_LIBCPP_FUNC_VIS
52size_t __next_prime(size_t __n);
53
54template <class _NodePtr>
55struct __hash_node_base
56{
57    typedef typename pointer_traits<_NodePtr>::element_type __node_type;
58    typedef __hash_node_base __first_node;
59    typedef typename __rebind_pointer<_NodePtr, __first_node>::type __node_base_pointer;
60    typedef _NodePtr __node_pointer;
61
62#if defined(_LIBCPP_ABI_FIX_UNORDERED_NODE_POINTER_UB)
63  typedef __node_base_pointer __next_pointer;
64#else
65  typedef typename conditional<
66      is_pointer<__node_pointer>::value,
67      __node_base_pointer,
68      __node_pointer>::type   __next_pointer;
69#endif
70
71    __next_pointer    __next_;
72
73    _LIBCPP_INLINE_VISIBILITY
74    __next_pointer __ptr() _NOEXCEPT {
75        return static_cast<__next_pointer>(
76            pointer_traits<__node_base_pointer>::pointer_to(*this));
77    }
78
79    _LIBCPP_INLINE_VISIBILITY
80    __node_pointer __upcast() _NOEXCEPT {
81        return static_cast<__node_pointer>(
82            pointer_traits<__node_base_pointer>::pointer_to(*this));
83    }
84
85    _LIBCPP_INLINE_VISIBILITY
86    size_t __hash() const _NOEXCEPT {
87        return static_cast<__node_type const&>(*this).__hash_;
88    }
89
90    _LIBCPP_INLINE_VISIBILITY __hash_node_base() _NOEXCEPT : __next_(nullptr) {}
91};
92
93template <class _Tp, class _VoidPtr>
94struct __hash_node
95    : public __hash_node_base
96             <
97                 typename __rebind_pointer<_VoidPtr, __hash_node<_Tp, _VoidPtr> >::type
98             >
99{
100    typedef _Tp __node_value_type;
101
102    size_t            __hash_;
103    __node_value_type __value_;
104};
105
106inline _LIBCPP_INLINE_VISIBILITY
107bool
108__is_hash_power2(size_t __bc)
109{
110    return __bc > 2 && !(__bc & (__bc - 1));
111}
112
113inline _LIBCPP_INLINE_VISIBILITY
114size_t
115__constrain_hash(size_t __h, size_t __bc)
116{
117    return !(__bc & (__bc - 1)) ? __h & (__bc - 1) :
118        (__h < __bc ? __h : __h % __bc);
119}
120
121inline _LIBCPP_INLINE_VISIBILITY
122size_t
123__next_hash_pow2(size_t __n)
124{
125    return __n < 2 ? __n : (size_t(1) << (std::numeric_limits<size_t>::digits - __libcpp_clz(__n-1)));
126}
127
128
129template <class _Tp, class _Hash, class _Equal, class _Alloc> class __hash_table;
130
131template <class _NodePtr>      class _LIBCPP_TEMPLATE_VIS __hash_iterator;
132template <class _ConstNodePtr> class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
133template <class _NodePtr>      class _LIBCPP_TEMPLATE_VIS __hash_local_iterator;
134template <class _ConstNodePtr> class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
135template <class _HashIterator> class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
136template <class _HashIterator> class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
137
138template <class _Tp>
139struct __hash_key_value_types {
140  static_assert(!is_reference<_Tp>::value && !is_const<_Tp>::value, "");
141  typedef _Tp key_type;
142  typedef _Tp __node_value_type;
143  typedef _Tp __container_value_type;
144  static const bool __is_map = false;
145
146  _LIBCPP_INLINE_VISIBILITY
147  static key_type const& __get_key(_Tp const& __v) {
148    return __v;
149  }
150  _LIBCPP_INLINE_VISIBILITY
151  static __container_value_type const& __get_value(__node_value_type const& __v) {
152    return __v;
153  }
154  _LIBCPP_INLINE_VISIBILITY
155  static __container_value_type* __get_ptr(__node_value_type& __n) {
156    return _VSTD::addressof(__n);
157  }
158#ifndef _LIBCPP_CXX03_LANG
159  _LIBCPP_INLINE_VISIBILITY
160  static __container_value_type&& __move(__node_value_type& __v) {
161    return _VSTD::move(__v);
162  }
163#endif
164};
165
166template <class _Key, class _Tp>
167struct __hash_key_value_types<__hash_value_type<_Key, _Tp> > {
168  typedef _Key                                         key_type;
169  typedef _Tp                                          mapped_type;
170  typedef __hash_value_type<_Key, _Tp>                 __node_value_type;
171  typedef pair<const _Key, _Tp>                        __container_value_type;
172  typedef __container_value_type                       __map_value_type;
173  static const bool __is_map = true;
174
175  _LIBCPP_INLINE_VISIBILITY
176  static key_type const& __get_key(__container_value_type const& __v) {
177    return __v.first;
178  }
179
180  template <class _Up>
181  _LIBCPP_INLINE_VISIBILITY
182  static typename enable_if<__is_same_uncvref<_Up, __node_value_type>::value,
183      __container_value_type const&>::type
184  __get_value(_Up& __t) {
185    return __t.__get_value();
186  }
187
188  template <class _Up>
189  _LIBCPP_INLINE_VISIBILITY
190  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value,
191      __container_value_type const&>::type
192  __get_value(_Up& __t) {
193    return __t;
194  }
195
196  _LIBCPP_INLINE_VISIBILITY
197  static __container_value_type* __get_ptr(__node_value_type& __n) {
198    return _VSTD::addressof(__n.__get_value());
199  }
200#ifndef _LIBCPP_CXX03_LANG
201  _LIBCPP_INLINE_VISIBILITY
202  static pair<key_type&&, mapped_type&&> __move(__node_value_type& __v) {
203    return __v.__move();
204  }
205#endif
206
207};
208
209template <class _Tp, class _AllocPtr, class _KVTypes = __hash_key_value_types<_Tp>,
210          bool = _KVTypes::__is_map>
211struct __hash_map_pointer_types {};
212
213template <class _Tp, class _AllocPtr, class _KVTypes>
214struct __hash_map_pointer_types<_Tp, _AllocPtr, _KVTypes, true> {
215  typedef typename _KVTypes::__map_value_type   _Mv;
216  typedef typename __rebind_pointer<_AllocPtr, _Mv>::type
217                                                       __map_value_type_pointer;
218  typedef typename __rebind_pointer<_AllocPtr, const _Mv>::type
219                                                 __const_map_value_type_pointer;
220};
221
222template <class _NodePtr, class _NodeT = typename pointer_traits<_NodePtr>::element_type>
223struct __hash_node_types;
224
225template <class _NodePtr, class _Tp, class _VoidPtr>
226struct __hash_node_types<_NodePtr, __hash_node<_Tp, _VoidPtr> >
227    : public __hash_key_value_types<_Tp>, __hash_map_pointer_types<_Tp, _VoidPtr>
228
229{
230  typedef __hash_key_value_types<_Tp>           __base;
231
232public:
233  typedef ptrdiff_t difference_type;
234  typedef size_t size_type;
235
236  typedef typename __rebind_pointer<_NodePtr, void>::type       __void_pointer;
237
238  typedef typename pointer_traits<_NodePtr>::element_type       __node_type;
239  typedef _NodePtr                                              __node_pointer;
240
241  typedef __hash_node_base<__node_pointer>                      __node_base_type;
242  typedef typename __rebind_pointer<_NodePtr, __node_base_type>::type
243                                                             __node_base_pointer;
244
245  typedef typename __node_base_type::__next_pointer          __next_pointer;
246
247  typedef _Tp                                                 __node_value_type;
248  typedef typename __rebind_pointer<_VoidPtr, __node_value_type>::type
249                                                      __node_value_type_pointer;
250  typedef typename __rebind_pointer<_VoidPtr, const __node_value_type>::type
251                                                __const_node_value_type_pointer;
252
253private:
254    static_assert(!is_const<__node_type>::value,
255                "_NodePtr should never be a pointer to const");
256    static_assert((is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value),
257                  "_VoidPtr does not point to unqualified void type");
258    static_assert((is_same<typename __rebind_pointer<_VoidPtr, __node_type>::type,
259                          _NodePtr>::value), "_VoidPtr does not rebind to _NodePtr.");
260};
261
262template <class _HashIterator>
263struct __hash_node_types_from_iterator;
264template <class _NodePtr>
265struct __hash_node_types_from_iterator<__hash_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
266template <class _NodePtr>
267struct __hash_node_types_from_iterator<__hash_const_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
268template <class _NodePtr>
269struct __hash_node_types_from_iterator<__hash_local_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
270template <class _NodePtr>
271struct __hash_node_types_from_iterator<__hash_const_local_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
272
273
274template <class _NodeValueTp, class _VoidPtr>
275struct __make_hash_node_types {
276  typedef __hash_node<_NodeValueTp, _VoidPtr> _NodeTp;
277  typedef typename __rebind_pointer<_VoidPtr, _NodeTp>::type _NodePtr;
278  typedef __hash_node_types<_NodePtr> type;
279};
280
281template <class _NodePtr>
282class _LIBCPP_TEMPLATE_VIS __hash_iterator
283{
284    typedef __hash_node_types<_NodePtr> _NodeTypes;
285    typedef _NodePtr                            __node_pointer;
286    typedef typename _NodeTypes::__next_pointer __next_pointer;
287
288    __next_pointer            __node_;
289
290public:
291    typedef forward_iterator_tag                           iterator_category;
292    typedef typename _NodeTypes::__node_value_type         value_type;
293    typedef typename _NodeTypes::difference_type           difference_type;
294    typedef value_type&                                    reference;
295    typedef typename _NodeTypes::__node_value_type_pointer pointer;
296
297    _LIBCPP_INLINE_VISIBILITY __hash_iterator() _NOEXCEPT : __node_(nullptr) {
298#if _LIBCPP_DEBUG_LEVEL == 2
299        __get_db()->__insert_i(this);
300#endif
301    }
302
303#if _LIBCPP_DEBUG_LEVEL == 2
304    _LIBCPP_INLINE_VISIBILITY
305    __hash_iterator(const __hash_iterator& __i)
306        : __node_(__i.__node_)
307    {
308        __get_db()->__iterator_copy(this, &__i);
309    }
310
311    _LIBCPP_INLINE_VISIBILITY
312    ~__hash_iterator()
313    {
314        __get_db()->__erase_i(this);
315    }
316
317    _LIBCPP_INLINE_VISIBILITY
318    __hash_iterator& operator=(const __hash_iterator& __i)
319    {
320        if (this != &__i)
321        {
322            __get_db()->__iterator_copy(this, &__i);
323            __node_ = __i.__node_;
324        }
325        return *this;
326    }
327#endif  // _LIBCPP_DEBUG_LEVEL == 2
328
329    _LIBCPP_INLINE_VISIBILITY
330    reference operator*() const {
331        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
332                             "Attempted to dereference a non-dereferenceable unordered container iterator");
333        return __node_->__upcast()->__value_;
334    }
335
336    _LIBCPP_INLINE_VISIBILITY
337    pointer operator->() const {
338        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
339                           "Attempted to dereference a non-dereferenceable unordered container iterator");
340        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
341    }
342
343    _LIBCPP_INLINE_VISIBILITY
344    __hash_iterator& operator++() {
345        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
346                       "Attempted to increment non-incrementable unordered container iterator");
347        __node_ = __node_->__next_;
348        return *this;
349    }
350
351    _LIBCPP_INLINE_VISIBILITY
352    __hash_iterator operator++(int)
353    {
354        __hash_iterator __t(*this);
355        ++(*this);
356        return __t;
357    }
358
359    friend _LIBCPP_INLINE_VISIBILITY
360    bool operator==(const __hash_iterator& __x, const __hash_iterator& __y)
361    {
362        return __x.__node_ == __y.__node_;
363    }
364    friend _LIBCPP_INLINE_VISIBILITY
365    bool operator!=(const __hash_iterator& __x, const __hash_iterator& __y)
366        {return !(__x == __y);}
367
368private:
369#if _LIBCPP_DEBUG_LEVEL == 2
370    _LIBCPP_INLINE_VISIBILITY
371    __hash_iterator(__next_pointer __node, const void* __c) _NOEXCEPT
372        : __node_(__node)
373        {
374            __get_db()->__insert_ic(this, __c);
375        }
376#else
377    _LIBCPP_INLINE_VISIBILITY
378    __hash_iterator(__next_pointer __node) _NOEXCEPT
379        : __node_(__node)
380        {}
381#endif
382    template <class, class, class, class> friend class __hash_table;
383    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
384    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
385    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
386    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
387};
388
389template <class _NodePtr>
390class _LIBCPP_TEMPLATE_VIS __hash_const_iterator
391{
392    static_assert(!is_const<typename pointer_traits<_NodePtr>::element_type>::value, "");
393    typedef __hash_node_types<_NodePtr> _NodeTypes;
394    typedef _NodePtr                            __node_pointer;
395    typedef typename _NodeTypes::__next_pointer __next_pointer;
396
397    __next_pointer __node_;
398
399public:
400    typedef __hash_iterator<_NodePtr> __non_const_iterator;
401
402    typedef forward_iterator_tag                                 iterator_category;
403    typedef typename _NodeTypes::__node_value_type               value_type;
404    typedef typename _NodeTypes::difference_type                 difference_type;
405    typedef const value_type&                                    reference;
406    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;
407
408
409    _LIBCPP_INLINE_VISIBILITY __hash_const_iterator() _NOEXCEPT : __node_(nullptr) {
410#if _LIBCPP_DEBUG_LEVEL == 2
411        __get_db()->__insert_i(this);
412#endif
413    }
414
415    _LIBCPP_INLINE_VISIBILITY
416    __hash_const_iterator(const __non_const_iterator& __x) _NOEXCEPT
417        : __node_(__x.__node_)
418    {
419#if _LIBCPP_DEBUG_LEVEL == 2
420        __get_db()->__iterator_copy(this, &__x);
421#endif
422    }
423
424#if _LIBCPP_DEBUG_LEVEL == 2
425    _LIBCPP_INLINE_VISIBILITY
426    __hash_const_iterator(const __hash_const_iterator& __i)
427        : __node_(__i.__node_)
428    {
429        __get_db()->__iterator_copy(this, &__i);
430    }
431
432    _LIBCPP_INLINE_VISIBILITY
433    ~__hash_const_iterator()
434    {
435        __get_db()->__erase_i(this);
436    }
437
438    _LIBCPP_INLINE_VISIBILITY
439    __hash_const_iterator& operator=(const __hash_const_iterator& __i)
440    {
441        if (this != &__i)
442        {
443            __get_db()->__iterator_copy(this, &__i);
444            __node_ = __i.__node_;
445        }
446        return *this;
447    }
448#endif  // _LIBCPP_DEBUG_LEVEL == 2
449
450    _LIBCPP_INLINE_VISIBILITY
451    reference operator*() const {
452        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
453                           "Attempted to dereference a non-dereferenceable unordered container const_iterator");
454        return __node_->__upcast()->__value_;
455    }
456    _LIBCPP_INLINE_VISIBILITY
457    pointer operator->() const {
458        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
459                           "Attempted to dereference a non-dereferenceable unordered container const_iterator");
460        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
461    }
462
463    _LIBCPP_INLINE_VISIBILITY
464    __hash_const_iterator& operator++() {
465        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
466                             "Attempted to increment non-incrementable unordered container const_iterator");
467        __node_ = __node_->__next_;
468        return *this;
469    }
470
471    _LIBCPP_INLINE_VISIBILITY
472    __hash_const_iterator operator++(int)
473    {
474        __hash_const_iterator __t(*this);
475        ++(*this);
476        return __t;
477    }
478
479    friend _LIBCPP_INLINE_VISIBILITY
480    bool operator==(const __hash_const_iterator& __x, const __hash_const_iterator& __y)
481    {
482        return __x.__node_ == __y.__node_;
483    }
484    friend _LIBCPP_INLINE_VISIBILITY
485    bool operator!=(const __hash_const_iterator& __x, const __hash_const_iterator& __y)
486        {return !(__x == __y);}
487
488private:
489#if _LIBCPP_DEBUG_LEVEL == 2
490    _LIBCPP_INLINE_VISIBILITY
491    __hash_const_iterator(__next_pointer __node, const void* __c) _NOEXCEPT
492        : __node_(__node)
493        {
494            __get_db()->__insert_ic(this, __c);
495        }
496#else
497    _LIBCPP_INLINE_VISIBILITY
498    __hash_const_iterator(__next_pointer __node) _NOEXCEPT
499        : __node_(__node)
500        {}
501#endif
502    template <class, class, class, class> friend class __hash_table;
503    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
504    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
505    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
506};
507
508template <class _NodePtr>
509class _LIBCPP_TEMPLATE_VIS __hash_local_iterator
510{
511    typedef __hash_node_types<_NodePtr> _NodeTypes;
512    typedef _NodePtr                            __node_pointer;
513    typedef typename _NodeTypes::__next_pointer __next_pointer;
514
515    __next_pointer         __node_;
516    size_t                 __bucket_;
517    size_t                 __bucket_count_;
518
519public:
520    typedef forward_iterator_tag                                iterator_category;
521    typedef typename _NodeTypes::__node_value_type              value_type;
522    typedef typename _NodeTypes::difference_type                difference_type;
523    typedef value_type&                                         reference;
524    typedef typename _NodeTypes::__node_value_type_pointer      pointer;
525
526    _LIBCPP_INLINE_VISIBILITY __hash_local_iterator() _NOEXCEPT : __node_(nullptr) {
527#if _LIBCPP_DEBUG_LEVEL == 2
528        __get_db()->__insert_i(this);
529#endif
530    }
531
532#if _LIBCPP_DEBUG_LEVEL == 2
533    _LIBCPP_INLINE_VISIBILITY
534    __hash_local_iterator(const __hash_local_iterator& __i)
535        : __node_(__i.__node_),
536          __bucket_(__i.__bucket_),
537          __bucket_count_(__i.__bucket_count_)
538    {
539        __get_db()->__iterator_copy(this, &__i);
540    }
541
542    _LIBCPP_INLINE_VISIBILITY
543    ~__hash_local_iterator()
544    {
545        __get_db()->__erase_i(this);
546    }
547
548    _LIBCPP_INLINE_VISIBILITY
549    __hash_local_iterator& operator=(const __hash_local_iterator& __i)
550    {
551        if (this != &__i)
552        {
553            __get_db()->__iterator_copy(this, &__i);
554            __node_ = __i.__node_;
555            __bucket_ = __i.__bucket_;
556            __bucket_count_ = __i.__bucket_count_;
557        }
558        return *this;
559    }
560#endif  // _LIBCPP_DEBUG_LEVEL == 2
561
562    _LIBCPP_INLINE_VISIBILITY
563    reference operator*() const {
564        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
565                           "Attempted to dereference a non-dereferenceable unordered container local_iterator");
566        return __node_->__upcast()->__value_;
567    }
568
569    _LIBCPP_INLINE_VISIBILITY
570    pointer operator->() const {
571        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
572                             "Attempted to dereference a non-dereferenceable unordered container local_iterator");
573        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
574    }
575
576    _LIBCPP_INLINE_VISIBILITY
577    __hash_local_iterator& operator++() {
578        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
579                       "Attempted to increment non-incrementable unordered container local_iterator");
580        __node_ = __node_->__next_;
581        if (__node_ != nullptr && __constrain_hash(__node_->__hash(), __bucket_count_) != __bucket_)
582            __node_ = nullptr;
583        return *this;
584    }
585
586    _LIBCPP_INLINE_VISIBILITY
587    __hash_local_iterator operator++(int)
588    {
589        __hash_local_iterator __t(*this);
590        ++(*this);
591        return __t;
592    }
593
594    friend _LIBCPP_INLINE_VISIBILITY
595    bool operator==(const __hash_local_iterator& __x, const __hash_local_iterator& __y)
596    {
597        return __x.__node_ == __y.__node_;
598    }
599    friend _LIBCPP_INLINE_VISIBILITY
600    bool operator!=(const __hash_local_iterator& __x, const __hash_local_iterator& __y)
601        {return !(__x == __y);}
602
603private:
604#if _LIBCPP_DEBUG_LEVEL == 2
605    _LIBCPP_INLINE_VISIBILITY
606    __hash_local_iterator(__next_pointer __node, size_t __bucket,
607                          size_t __bucket_count, const void* __c) _NOEXCEPT
608        : __node_(__node),
609          __bucket_(__bucket),
610          __bucket_count_(__bucket_count)
611        {
612            __get_db()->__insert_ic(this, __c);
613            if (__node_ != nullptr)
614                __node_ = __node_->__next_;
615        }
616#else
617    _LIBCPP_INLINE_VISIBILITY
618    __hash_local_iterator(__next_pointer __node, size_t __bucket,
619                          size_t __bucket_count) _NOEXCEPT
620        : __node_(__node),
621          __bucket_(__bucket),
622          __bucket_count_(__bucket_count)
623        {
624            if (__node_ != nullptr)
625                __node_ = __node_->__next_;
626        }
627#endif
628    template <class, class, class, class> friend class __hash_table;
629    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
630    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
631};
632
633template <class _ConstNodePtr>
634class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator
635{
636    typedef __hash_node_types<_ConstNodePtr> _NodeTypes;
637    typedef _ConstNodePtr                       __node_pointer;
638    typedef typename _NodeTypes::__next_pointer __next_pointer;
639
640    __next_pointer         __node_;
641    size_t                 __bucket_;
642    size_t                 __bucket_count_;
643
644    typedef pointer_traits<__node_pointer>          __pointer_traits;
645    typedef typename __pointer_traits::element_type __node;
646    typedef typename remove_const<__node>::type     __non_const_node;
647    typedef typename __rebind_pointer<__node_pointer, __non_const_node>::type
648        __non_const_node_pointer;
649public:
650    typedef __hash_local_iterator<__non_const_node_pointer>
651                                                    __non_const_iterator;
652
653    typedef forward_iterator_tag                                 iterator_category;
654    typedef typename _NodeTypes::__node_value_type               value_type;
655    typedef typename _NodeTypes::difference_type                 difference_type;
656    typedef const value_type&                                    reference;
657    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;
658
659
660    _LIBCPP_INLINE_VISIBILITY __hash_const_local_iterator() _NOEXCEPT : __node_(nullptr) {
661#if _LIBCPP_DEBUG_LEVEL == 2
662        __get_db()->__insert_i(this);
663#endif
664    }
665
666    _LIBCPP_INLINE_VISIBILITY
667    __hash_const_local_iterator(const __non_const_iterator& __x) _NOEXCEPT
668        : __node_(__x.__node_),
669          __bucket_(__x.__bucket_),
670          __bucket_count_(__x.__bucket_count_)
671    {
672#if _LIBCPP_DEBUG_LEVEL == 2
673        __get_db()->__iterator_copy(this, &__x);
674#endif
675    }
676
677#if _LIBCPP_DEBUG_LEVEL == 2
678    _LIBCPP_INLINE_VISIBILITY
679    __hash_const_local_iterator(const __hash_const_local_iterator& __i)
680        : __node_(__i.__node_),
681          __bucket_(__i.__bucket_),
682          __bucket_count_(__i.__bucket_count_)
683    {
684        __get_db()->__iterator_copy(this, &__i);
685    }
686
687    _LIBCPP_INLINE_VISIBILITY
688    ~__hash_const_local_iterator()
689    {
690        __get_db()->__erase_i(this);
691    }
692
693    _LIBCPP_INLINE_VISIBILITY
694    __hash_const_local_iterator& operator=(const __hash_const_local_iterator& __i)
695    {
696        if (this != &__i)
697        {
698            __get_db()->__iterator_copy(this, &__i);
699            __node_ = __i.__node_;
700            __bucket_ = __i.__bucket_;
701            __bucket_count_ = __i.__bucket_count_;
702        }
703        return *this;
704    }
705#endif  // _LIBCPP_DEBUG_LEVEL == 2
706
707    _LIBCPP_INLINE_VISIBILITY
708    reference operator*() const {
709        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
710                           "Attempted to dereference a non-dereferenceable unordered container const_local_iterator");
711        return __node_->__upcast()->__value_;
712    }
713
714    _LIBCPP_INLINE_VISIBILITY
715    pointer operator->() const {
716        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
717                           "Attempted to dereference a non-dereferenceable unordered container const_local_iterator");
718        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
719    }
720
721    _LIBCPP_INLINE_VISIBILITY
722    __hash_const_local_iterator& operator++() {
723        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
724                       "Attempted to increment non-incrementable unordered container const_local_iterator");
725        __node_ = __node_->__next_;
726        if (__node_ != nullptr && __constrain_hash(__node_->__hash(), __bucket_count_) != __bucket_)
727            __node_ = nullptr;
728        return *this;
729    }
730
731    _LIBCPP_INLINE_VISIBILITY
732    __hash_const_local_iterator operator++(int)
733    {
734        __hash_const_local_iterator __t(*this);
735        ++(*this);
736        return __t;
737    }
738
739    friend _LIBCPP_INLINE_VISIBILITY
740    bool operator==(const __hash_const_local_iterator& __x, const __hash_const_local_iterator& __y)
741    {
742        return __x.__node_ == __y.__node_;
743    }
744    friend _LIBCPP_INLINE_VISIBILITY
745    bool operator!=(const __hash_const_local_iterator& __x, const __hash_const_local_iterator& __y)
746        {return !(__x == __y);}
747
748private:
749#if _LIBCPP_DEBUG_LEVEL == 2
750    _LIBCPP_INLINE_VISIBILITY
751    __hash_const_local_iterator(__next_pointer __node, size_t __bucket,
752                                size_t __bucket_count, const void* __c) _NOEXCEPT
753        : __node_(__node),
754          __bucket_(__bucket),
755          __bucket_count_(__bucket_count)
756        {
757            __get_db()->__insert_ic(this, __c);
758            if (__node_ != nullptr)
759                __node_ = __node_->__next_;
760        }
761#else
762    _LIBCPP_INLINE_VISIBILITY
763    __hash_const_local_iterator(__next_pointer __node, size_t __bucket,
764                                size_t __bucket_count) _NOEXCEPT
765        : __node_(__node),
766          __bucket_(__bucket),
767          __bucket_count_(__bucket_count)
768        {
769            if (__node_ != nullptr)
770                __node_ = __node_->__next_;
771        }
772#endif
773    template <class, class, class, class> friend class __hash_table;
774    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
775};
776
777template <class _Alloc>
778class __bucket_list_deallocator
779{
780    typedef _Alloc                                          allocator_type;
781    typedef allocator_traits<allocator_type>                __alloc_traits;
782    typedef typename __alloc_traits::size_type              size_type;
783
784    __compressed_pair<size_type, allocator_type> __data_;
785public:
786    typedef typename __alloc_traits::pointer pointer;
787
788    _LIBCPP_INLINE_VISIBILITY
789    __bucket_list_deallocator()
790        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
791        : __data_(0, __default_init_tag()) {}
792
793    _LIBCPP_INLINE_VISIBILITY
794    __bucket_list_deallocator(const allocator_type& __a, size_type __size)
795        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
796        : __data_(__size, __a) {}
797
798#ifndef _LIBCPP_CXX03_LANG
799    _LIBCPP_INLINE_VISIBILITY
800    __bucket_list_deallocator(__bucket_list_deallocator&& __x)
801        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
802        : __data_(_VSTD::move(__x.__data_))
803    {
804        __x.size() = 0;
805    }
806#endif
807
808    _LIBCPP_INLINE_VISIBILITY
809    size_type& size() _NOEXCEPT {return __data_.first();}
810    _LIBCPP_INLINE_VISIBILITY
811    size_type  size() const _NOEXCEPT {return __data_.first();}
812
813    _LIBCPP_INLINE_VISIBILITY
814    allocator_type& __alloc() _NOEXCEPT {return __data_.second();}
815    _LIBCPP_INLINE_VISIBILITY
816    const allocator_type& __alloc() const _NOEXCEPT {return __data_.second();}
817
818    _LIBCPP_INLINE_VISIBILITY
819    void operator()(pointer __p) _NOEXCEPT
820    {
821        __alloc_traits::deallocate(__alloc(), __p, size());
822    }
823};
824
825template <class _Alloc> class __hash_map_node_destructor;
826
827template <class _Alloc>
828class __hash_node_destructor
829{
830    typedef _Alloc                                          allocator_type;
831    typedef allocator_traits<allocator_type>                __alloc_traits;
832
833public:
834    typedef typename __alloc_traits::pointer                pointer;
835private:
836    typedef __hash_node_types<pointer> _NodeTypes;
837
838    allocator_type& __na_;
839
840public:
841    bool __value_constructed;
842
843    __hash_node_destructor(__hash_node_destructor const&) = default;
844    __hash_node_destructor& operator=(const __hash_node_destructor&) = delete;
845
846
847    _LIBCPP_INLINE_VISIBILITY
848    explicit __hash_node_destructor(allocator_type& __na,
849                                    bool __constructed = false) _NOEXCEPT
850        : __na_(__na),
851          __value_constructed(__constructed)
852        {}
853
854    _LIBCPP_INLINE_VISIBILITY
855    void operator()(pointer __p) _NOEXCEPT
856    {
857        if (__value_constructed)
858            __alloc_traits::destroy(__na_, _NodeTypes::__get_ptr(__p->__value_));
859        if (__p)
860            __alloc_traits::deallocate(__na_, __p, 1);
861    }
862
863    template <class> friend class __hash_map_node_destructor;
864};
865
866#if _LIBCPP_STD_VER > 14
867template <class _NodeType, class _Alloc>
868struct __generic_container_node_destructor;
869
870template <class _Tp, class _VoidPtr, class _Alloc>
871struct __generic_container_node_destructor<__hash_node<_Tp, _VoidPtr>, _Alloc>
872    : __hash_node_destructor<_Alloc>
873{
874    using __hash_node_destructor<_Alloc>::__hash_node_destructor;
875};
876#endif
877
878template <class _Key, class _Hash, class _Equal>
879struct __enforce_unordered_container_requirements {
880#ifndef _LIBCPP_CXX03_LANG
881    static_assert(__check_hash_requirements<_Key, _Hash>::value,
882    "the specified hash does not meet the Hash requirements");
883    static_assert(is_copy_constructible<_Equal>::value,
884    "the specified comparator is required to be copy constructible");
885#endif
886    typedef int type;
887};
888
889template <class _Key, class _Hash, class _Equal>
890#ifndef _LIBCPP_CXX03_LANG
891    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Equal const&, _Key const&, _Key const&>::value,
892    "the specified comparator type does not provide a viable const call operator")
893    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Hash const&, _Key const&>::value,
894    "the specified hash functor does not provide a viable const call operator")
895#endif
896typename __enforce_unordered_container_requirements<_Key, _Hash, _Equal>::type
897__diagnose_unordered_container_requirements(int);
898
899// This dummy overload is used so that the compiler won't emit a spurious
900// "no matching function for call to __diagnose_unordered_xxx" diagnostic
901// when the overload above causes a hard error.
902template <class _Key, class _Hash, class _Equal>
903int __diagnose_unordered_container_requirements(void*);
904
905template <class _Tp, class _Hash, class _Equal, class _Alloc>
906class __hash_table
907{
908public:
909    typedef _Tp    value_type;
910    typedef _Hash  hasher;
911    typedef _Equal key_equal;
912    typedef _Alloc allocator_type;
913
914private:
915    typedef allocator_traits<allocator_type> __alloc_traits;
916    typedef typename
917      __make_hash_node_types<value_type, typename __alloc_traits::void_pointer>::type
918                                                                     _NodeTypes;
919public:
920
921    typedef typename _NodeTypes::__node_value_type           __node_value_type;
922    typedef typename _NodeTypes::__container_value_type      __container_value_type;
923    typedef typename _NodeTypes::key_type                    key_type;
924    typedef value_type&                              reference;
925    typedef const value_type&                        const_reference;
926    typedef typename __alloc_traits::pointer         pointer;
927    typedef typename __alloc_traits::const_pointer   const_pointer;
928#ifndef _LIBCPP_ABI_FIX_UNORDERED_CONTAINER_SIZE_TYPE
929    typedef typename __alloc_traits::size_type       size_type;
930#else
931    typedef typename _NodeTypes::size_type           size_type;
932#endif
933    typedef typename _NodeTypes::difference_type     difference_type;
934public:
935    // Create __node
936
937    typedef typename _NodeTypes::__node_type __node;
938    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
939    typedef allocator_traits<__node_allocator>       __node_traits;
940    typedef typename _NodeTypes::__void_pointer      __void_pointer;
941    typedef typename _NodeTypes::__node_pointer      __node_pointer;
942    typedef typename _NodeTypes::__node_pointer      __node_const_pointer;
943    typedef typename _NodeTypes::__node_base_type    __first_node;
944    typedef typename _NodeTypes::__node_base_pointer __node_base_pointer;
945    typedef typename _NodeTypes::__next_pointer      __next_pointer;
946
947private:
948    // check for sane allocator pointer rebinding semantics. Rebinding the
949    // allocator for a new pointer type should be exactly the same as rebinding
950    // the pointer using 'pointer_traits'.
951    static_assert((is_same<__node_pointer, typename __node_traits::pointer>::value),
952                  "Allocator does not rebind pointers in a sane manner.");
953    typedef typename __rebind_alloc_helper<__node_traits, __first_node>::type
954        __node_base_allocator;
955    typedef allocator_traits<__node_base_allocator> __node_base_traits;
956    static_assert((is_same<__node_base_pointer, typename __node_base_traits::pointer>::value),
957                 "Allocator does not rebind pointers in a sane manner.");
958
959private:
960
961    typedef typename __rebind_alloc_helper<__node_traits, __next_pointer>::type __pointer_allocator;
962    typedef __bucket_list_deallocator<__pointer_allocator> __bucket_list_deleter;
963    typedef unique_ptr<__next_pointer[], __bucket_list_deleter> __bucket_list;
964    typedef allocator_traits<__pointer_allocator>          __pointer_alloc_traits;
965    typedef typename __bucket_list_deleter::pointer       __node_pointer_pointer;
966
967    // --- Member data begin ---
968    __bucket_list                                         __bucket_list_;
969    __compressed_pair<__first_node, __node_allocator>     __p1_;
970    __compressed_pair<size_type, hasher>                  __p2_;
971    __compressed_pair<float, key_equal>                   __p3_;
972    // --- Member data end ---
973
974    _LIBCPP_INLINE_VISIBILITY
975    size_type& size() _NOEXCEPT {return __p2_.first();}
976public:
977    _LIBCPP_INLINE_VISIBILITY
978    size_type  size() const _NOEXCEPT {return __p2_.first();}
979
980    _LIBCPP_INLINE_VISIBILITY
981    hasher& hash_function() _NOEXCEPT {return __p2_.second();}
982    _LIBCPP_INLINE_VISIBILITY
983    const hasher& hash_function() const _NOEXCEPT {return __p2_.second();}
984
985    _LIBCPP_INLINE_VISIBILITY
986    float& max_load_factor() _NOEXCEPT {return __p3_.first();}
987    _LIBCPP_INLINE_VISIBILITY
988    float  max_load_factor() const _NOEXCEPT {return __p3_.first();}
989
990    _LIBCPP_INLINE_VISIBILITY
991    key_equal& key_eq() _NOEXCEPT {return __p3_.second();}
992    _LIBCPP_INLINE_VISIBILITY
993    const key_equal& key_eq() const _NOEXCEPT {return __p3_.second();}
994
995    _LIBCPP_INLINE_VISIBILITY
996    __node_allocator& __node_alloc() _NOEXCEPT {return __p1_.second();}
997    _LIBCPP_INLINE_VISIBILITY
998    const __node_allocator& __node_alloc() const _NOEXCEPT
999        {return __p1_.second();}
1000
1001public:
1002    typedef __hash_iterator<__node_pointer>                   iterator;
1003    typedef __hash_const_iterator<__node_pointer>             const_iterator;
1004    typedef __hash_local_iterator<__node_pointer>             local_iterator;
1005    typedef __hash_const_local_iterator<__node_pointer>       const_local_iterator;
1006
1007    _LIBCPP_INLINE_VISIBILITY
1008    __hash_table()
1009        _NOEXCEPT_(
1010            is_nothrow_default_constructible<__bucket_list>::value &&
1011            is_nothrow_default_constructible<__first_node>::value &&
1012            is_nothrow_default_constructible<__node_allocator>::value &&
1013            is_nothrow_default_constructible<hasher>::value &&
1014            is_nothrow_default_constructible<key_equal>::value);
1015    _LIBCPP_INLINE_VISIBILITY
1016    __hash_table(const hasher& __hf, const key_equal& __eql);
1017    __hash_table(const hasher& __hf, const key_equal& __eql,
1018                 const allocator_type& __a);
1019    explicit __hash_table(const allocator_type& __a);
1020    __hash_table(const __hash_table& __u);
1021    __hash_table(const __hash_table& __u, const allocator_type& __a);
1022#ifndef _LIBCPP_CXX03_LANG
1023    __hash_table(__hash_table&& __u)
1024        _NOEXCEPT_(
1025            is_nothrow_move_constructible<__bucket_list>::value &&
1026            is_nothrow_move_constructible<__first_node>::value &&
1027            is_nothrow_move_constructible<__node_allocator>::value &&
1028            is_nothrow_move_constructible<hasher>::value &&
1029            is_nothrow_move_constructible<key_equal>::value);
1030    __hash_table(__hash_table&& __u, const allocator_type& __a);
1031#endif  // _LIBCPP_CXX03_LANG
1032    ~__hash_table();
1033
1034    __hash_table& operator=(const __hash_table& __u);
1035#ifndef _LIBCPP_CXX03_LANG
1036    _LIBCPP_INLINE_VISIBILITY
1037    __hash_table& operator=(__hash_table&& __u)
1038        _NOEXCEPT_(
1039            __node_traits::propagate_on_container_move_assignment::value &&
1040            is_nothrow_move_assignable<__node_allocator>::value &&
1041            is_nothrow_move_assignable<hasher>::value &&
1042            is_nothrow_move_assignable<key_equal>::value);
1043#endif
1044    template <class _InputIterator>
1045        void __assign_unique(_InputIterator __first, _InputIterator __last);
1046    template <class _InputIterator>
1047        void __assign_multi(_InputIterator __first, _InputIterator __last);
1048
1049    _LIBCPP_INLINE_VISIBILITY
1050    size_type max_size() const _NOEXCEPT
1051    {
1052        return std::min<size_type>(
1053            __node_traits::max_size(__node_alloc()),
1054            numeric_limits<difference_type >::max()
1055        );
1056    }
1057
1058private:
1059    _LIBCPP_INLINE_VISIBILITY
1060    __next_pointer __node_insert_multi_prepare(size_t __cp_hash,
1061                                               value_type& __cp_val);
1062    _LIBCPP_INLINE_VISIBILITY
1063    void __node_insert_multi_perform(__node_pointer __cp,
1064                                     __next_pointer __pn) _NOEXCEPT;
1065
1066    _LIBCPP_INLINE_VISIBILITY
1067    __next_pointer __node_insert_unique_prepare(size_t __nd_hash,
1068                                                value_type& __nd_val);
1069    _LIBCPP_INLINE_VISIBILITY
1070    void __node_insert_unique_perform(__node_pointer __ptr) _NOEXCEPT;
1071
1072public:
1073    _LIBCPP_INLINE_VISIBILITY
1074    pair<iterator, bool> __node_insert_unique(__node_pointer __nd);
1075    _LIBCPP_INLINE_VISIBILITY
1076    iterator             __node_insert_multi(__node_pointer __nd);
1077    _LIBCPP_INLINE_VISIBILITY
1078    iterator             __node_insert_multi(const_iterator __p,
1079                                             __node_pointer __nd);
1080
1081#ifndef _LIBCPP_CXX03_LANG
1082    template <class _Key, class ..._Args>
1083    _LIBCPP_INLINE_VISIBILITY
1084    pair<iterator, bool> __emplace_unique_key_args(_Key const& __k, _Args&&... __args);
1085
1086    template <class... _Args>
1087    _LIBCPP_INLINE_VISIBILITY
1088    pair<iterator, bool> __emplace_unique_impl(_Args&&... __args);
1089
1090    template <class _Pp>
1091    _LIBCPP_INLINE_VISIBILITY
1092    pair<iterator, bool> __emplace_unique(_Pp&& __x) {
1093      return __emplace_unique_extract_key(_VSTD::forward<_Pp>(__x),
1094                                          __can_extract_key<_Pp, key_type>());
1095    }
1096
1097    template <class _First, class _Second>
1098    _LIBCPP_INLINE_VISIBILITY
1099    typename enable_if<
1100        __can_extract_map_key<_First, key_type, __container_value_type>::value,
1101        pair<iterator, bool>
1102    >::type __emplace_unique(_First&& __f, _Second&& __s) {
1103        return __emplace_unique_key_args(__f, _VSTD::forward<_First>(__f),
1104                                              _VSTD::forward<_Second>(__s));
1105    }
1106
1107    template <class... _Args>
1108    _LIBCPP_INLINE_VISIBILITY
1109    pair<iterator, bool> __emplace_unique(_Args&&... __args) {
1110      return __emplace_unique_impl(_VSTD::forward<_Args>(__args)...);
1111    }
1112
1113    template <class _Pp>
1114    _LIBCPP_INLINE_VISIBILITY
1115    pair<iterator, bool>
1116    __emplace_unique_extract_key(_Pp&& __x, __extract_key_fail_tag) {
1117      return __emplace_unique_impl(_VSTD::forward<_Pp>(__x));
1118    }
1119    template <class _Pp>
1120    _LIBCPP_INLINE_VISIBILITY
1121    pair<iterator, bool>
1122    __emplace_unique_extract_key(_Pp&& __x, __extract_key_self_tag) {
1123      return __emplace_unique_key_args(__x, _VSTD::forward<_Pp>(__x));
1124    }
1125    template <class _Pp>
1126    _LIBCPP_INLINE_VISIBILITY
1127    pair<iterator, bool>
1128    __emplace_unique_extract_key(_Pp&& __x, __extract_key_first_tag) {
1129      return __emplace_unique_key_args(__x.first, _VSTD::forward<_Pp>(__x));
1130    }
1131
1132    template <class... _Args>
1133    _LIBCPP_INLINE_VISIBILITY
1134    iterator __emplace_multi(_Args&&... __args);
1135    template <class... _Args>
1136    _LIBCPP_INLINE_VISIBILITY
1137    iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args);
1138
1139
1140    _LIBCPP_INLINE_VISIBILITY
1141    pair<iterator, bool>
1142    __insert_unique(__container_value_type&& __x) {
1143      return __emplace_unique_key_args(_NodeTypes::__get_key(__x), _VSTD::move(__x));
1144    }
1145
1146    template <class _Pp, class = typename enable_if<
1147            !__is_same_uncvref<_Pp, __container_value_type>::value
1148        >::type>
1149    _LIBCPP_INLINE_VISIBILITY
1150    pair<iterator, bool> __insert_unique(_Pp&& __x) {
1151      return __emplace_unique(_VSTD::forward<_Pp>(__x));
1152    }
1153
1154    template <class _Pp>
1155    _LIBCPP_INLINE_VISIBILITY
1156    iterator __insert_multi(_Pp&& __x) {
1157      return __emplace_multi(_VSTD::forward<_Pp>(__x));
1158    }
1159
1160    template <class _Pp>
1161    _LIBCPP_INLINE_VISIBILITY
1162    iterator __insert_multi(const_iterator __p, _Pp&& __x) {
1163        return __emplace_hint_multi(__p, _VSTD::forward<_Pp>(__x));
1164    }
1165
1166#else  // !defined(_LIBCPP_CXX03_LANG)
1167    template <class _Key, class _Args>
1168    _LIBCPP_INLINE_VISIBILITY
1169    pair<iterator, bool> __emplace_unique_key_args(_Key const&, _Args& __args);
1170
1171    iterator __insert_multi(const __container_value_type& __x);
1172    iterator __insert_multi(const_iterator __p, const __container_value_type& __x);
1173#endif
1174
1175    _LIBCPP_INLINE_VISIBILITY
1176    pair<iterator, bool> __insert_unique(const __container_value_type& __x) {
1177        return __emplace_unique_key_args(_NodeTypes::__get_key(__x), __x);
1178    }
1179
1180#if _LIBCPP_STD_VER > 14
1181    template <class _NodeHandle, class _InsertReturnType>
1182    _LIBCPP_INLINE_VISIBILITY
1183    _InsertReturnType __node_handle_insert_unique(_NodeHandle&& __nh);
1184    template <class _NodeHandle>
1185    _LIBCPP_INLINE_VISIBILITY
1186    iterator __node_handle_insert_unique(const_iterator __hint,
1187                                         _NodeHandle&& __nh);
1188    template <class _Table>
1189    _LIBCPP_INLINE_VISIBILITY
1190    void __node_handle_merge_unique(_Table& __source);
1191
1192    template <class _NodeHandle>
1193    _LIBCPP_INLINE_VISIBILITY
1194    iterator __node_handle_insert_multi(_NodeHandle&& __nh);
1195    template <class _NodeHandle>
1196    _LIBCPP_INLINE_VISIBILITY
1197    iterator __node_handle_insert_multi(const_iterator __hint, _NodeHandle&& __nh);
1198    template <class _Table>
1199    _LIBCPP_INLINE_VISIBILITY
1200    void __node_handle_merge_multi(_Table& __source);
1201
1202    template <class _NodeHandle>
1203    _LIBCPP_INLINE_VISIBILITY
1204    _NodeHandle __node_handle_extract(key_type const& __key);
1205    template <class _NodeHandle>
1206    _LIBCPP_INLINE_VISIBILITY
1207    _NodeHandle __node_handle_extract(const_iterator __it);
1208#endif
1209
1210    void clear() _NOEXCEPT;
1211    void rehash(size_type __n);
1212    _LIBCPP_INLINE_VISIBILITY void reserve(size_type __n)
1213        {rehash(static_cast<size_type>(ceil(__n / max_load_factor())));}
1214
1215    _LIBCPP_INLINE_VISIBILITY
1216    size_type bucket_count() const _NOEXCEPT
1217    {
1218        return __bucket_list_.get_deleter().size();
1219    }
1220
1221    _LIBCPP_INLINE_VISIBILITY
1222    iterator       begin() _NOEXCEPT;
1223    _LIBCPP_INLINE_VISIBILITY
1224    iterator       end() _NOEXCEPT;
1225    _LIBCPP_INLINE_VISIBILITY
1226    const_iterator begin() const _NOEXCEPT;
1227    _LIBCPP_INLINE_VISIBILITY
1228    const_iterator end() const _NOEXCEPT;
1229
1230    template <class _Key>
1231        _LIBCPP_INLINE_VISIBILITY
1232        size_type bucket(const _Key& __k) const
1233        {
1234            _LIBCPP_ASSERT(bucket_count() > 0,
1235                "unordered container::bucket(key) called when bucket_count() == 0");
1236            return __constrain_hash(hash_function()(__k), bucket_count());
1237        }
1238
1239    template <class _Key>
1240        iterator       find(const _Key& __x);
1241    template <class _Key>
1242        const_iterator find(const _Key& __x) const;
1243
1244    typedef __hash_node_destructor<__node_allocator> _Dp;
1245    typedef unique_ptr<__node, _Dp> __node_holder;
1246
1247    iterator erase(const_iterator __p);
1248    iterator erase(const_iterator __first, const_iterator __last);
1249    template <class _Key>
1250        size_type __erase_unique(const _Key& __k);
1251    template <class _Key>
1252        size_type __erase_multi(const _Key& __k);
1253    __node_holder remove(const_iterator __p) _NOEXCEPT;
1254
1255    template <class _Key>
1256        _LIBCPP_INLINE_VISIBILITY
1257        size_type __count_unique(const _Key& __k) const;
1258    template <class _Key>
1259        size_type __count_multi(const _Key& __k) const;
1260
1261    template <class _Key>
1262        pair<iterator, iterator>
1263        __equal_range_unique(const _Key& __k);
1264    template <class _Key>
1265        pair<const_iterator, const_iterator>
1266        __equal_range_unique(const _Key& __k) const;
1267
1268    template <class _Key>
1269        pair<iterator, iterator>
1270        __equal_range_multi(const _Key& __k);
1271    template <class _Key>
1272        pair<const_iterator, const_iterator>
1273        __equal_range_multi(const _Key& __k) const;
1274
1275    void swap(__hash_table& __u)
1276#if _LIBCPP_STD_VER <= 11
1277        _NOEXCEPT_(
1278            __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
1279            && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
1280                  || __is_nothrow_swappable<__pointer_allocator>::value)
1281            && (!__node_traits::propagate_on_container_swap::value
1282                  || __is_nothrow_swappable<__node_allocator>::value)
1283            );
1284#else
1285     _NOEXCEPT_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value);
1286#endif
1287
1288    _LIBCPP_INLINE_VISIBILITY
1289    size_type max_bucket_count() const _NOEXCEPT
1290        {return max_size(); }
1291    size_type bucket_size(size_type __n) const;
1292    _LIBCPP_INLINE_VISIBILITY float load_factor() const _NOEXCEPT
1293    {
1294        size_type __bc = bucket_count();
1295        return __bc != 0 ? (float)size() / __bc : 0.f;
1296    }
1297    _LIBCPP_INLINE_VISIBILITY void max_load_factor(float __mlf) _NOEXCEPT
1298    {
1299        _LIBCPP_ASSERT(__mlf > 0,
1300            "unordered container::max_load_factor(lf) called with lf <= 0");
1301        max_load_factor() = _VSTD::max(__mlf, load_factor());
1302    }
1303
1304    _LIBCPP_INLINE_VISIBILITY
1305    local_iterator
1306    begin(size_type __n)
1307    {
1308        _LIBCPP_ASSERT(__n < bucket_count(),
1309            "unordered container::begin(n) called with n >= bucket_count()");
1310#if _LIBCPP_DEBUG_LEVEL == 2
1311        return local_iterator(__bucket_list_[__n], __n, bucket_count(), this);
1312#else
1313        return local_iterator(__bucket_list_[__n], __n, bucket_count());
1314#endif
1315    }
1316
1317    _LIBCPP_INLINE_VISIBILITY
1318    local_iterator
1319    end(size_type __n)
1320    {
1321        _LIBCPP_ASSERT(__n < bucket_count(),
1322            "unordered container::end(n) called with n >= bucket_count()");
1323#if _LIBCPP_DEBUG_LEVEL == 2
1324        return local_iterator(nullptr, __n, bucket_count(), this);
1325#else
1326        return local_iterator(nullptr, __n, bucket_count());
1327#endif
1328    }
1329
1330    _LIBCPP_INLINE_VISIBILITY
1331    const_local_iterator
1332    cbegin(size_type __n) const
1333    {
1334        _LIBCPP_ASSERT(__n < bucket_count(),
1335            "unordered container::cbegin(n) called with n >= bucket_count()");
1336#if _LIBCPP_DEBUG_LEVEL == 2
1337        return const_local_iterator(__bucket_list_[__n], __n, bucket_count(), this);
1338#else
1339        return const_local_iterator(__bucket_list_[__n], __n, bucket_count());
1340#endif
1341    }
1342
1343    _LIBCPP_INLINE_VISIBILITY
1344    const_local_iterator
1345    cend(size_type __n) const
1346    {
1347        _LIBCPP_ASSERT(__n < bucket_count(),
1348            "unordered container::cend(n) called with n >= bucket_count()");
1349#if _LIBCPP_DEBUG_LEVEL == 2
1350        return const_local_iterator(nullptr, __n, bucket_count(), this);
1351#else
1352        return const_local_iterator(nullptr, __n, bucket_count());
1353#endif
1354    }
1355
1356#if _LIBCPP_DEBUG_LEVEL == 2
1357
1358    bool __dereferenceable(const const_iterator* __i) const;
1359    bool __decrementable(const const_iterator* __i) const;
1360    bool __addable(const const_iterator* __i, ptrdiff_t __n) const;
1361    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const;
1362
1363#endif  // _LIBCPP_DEBUG_LEVEL == 2
1364
1365private:
1366    void __rehash(size_type __n);
1367
1368#ifndef _LIBCPP_CXX03_LANG
1369    template <class ..._Args>
1370    __node_holder __construct_node(_Args&& ...__args);
1371
1372    template <class _First, class ..._Rest>
1373    __node_holder __construct_node_hash(size_t __hash, _First&& __f, _Rest&&... __rest);
1374#else // _LIBCPP_CXX03_LANG
1375    __node_holder __construct_node(const __container_value_type& __v);
1376    __node_holder __construct_node_hash(size_t __hash, const __container_value_type& __v);
1377#endif
1378
1379
1380    _LIBCPP_INLINE_VISIBILITY
1381    void __copy_assign_alloc(const __hash_table& __u)
1382        {__copy_assign_alloc(__u, integral_constant<bool,
1383             __node_traits::propagate_on_container_copy_assignment::value>());}
1384    void __copy_assign_alloc(const __hash_table& __u, true_type);
1385    _LIBCPP_INLINE_VISIBILITY
1386        void __copy_assign_alloc(const __hash_table&, false_type) {}
1387
1388#ifndef _LIBCPP_CXX03_LANG
1389    void __move_assign(__hash_table& __u, false_type);
1390    void __move_assign(__hash_table& __u, true_type)
1391        _NOEXCEPT_(
1392            is_nothrow_move_assignable<__node_allocator>::value &&
1393            is_nothrow_move_assignable<hasher>::value &&
1394            is_nothrow_move_assignable<key_equal>::value);
1395    _LIBCPP_INLINE_VISIBILITY
1396    void __move_assign_alloc(__hash_table& __u)
1397        _NOEXCEPT_(
1398            !__node_traits::propagate_on_container_move_assignment::value ||
1399            (is_nothrow_move_assignable<__pointer_allocator>::value &&
1400             is_nothrow_move_assignable<__node_allocator>::value))
1401        {__move_assign_alloc(__u, integral_constant<bool,
1402             __node_traits::propagate_on_container_move_assignment::value>());}
1403    _LIBCPP_INLINE_VISIBILITY
1404    void __move_assign_alloc(__hash_table& __u, true_type)
1405        _NOEXCEPT_(
1406            is_nothrow_move_assignable<__pointer_allocator>::value &&
1407            is_nothrow_move_assignable<__node_allocator>::value)
1408    {
1409        __bucket_list_.get_deleter().__alloc() =
1410                _VSTD::move(__u.__bucket_list_.get_deleter().__alloc());
1411        __node_alloc() = _VSTD::move(__u.__node_alloc());
1412    }
1413    _LIBCPP_INLINE_VISIBILITY
1414        void __move_assign_alloc(__hash_table&, false_type) _NOEXCEPT {}
1415#endif // _LIBCPP_CXX03_LANG
1416
1417    void __deallocate_node(__next_pointer __np) _NOEXCEPT;
1418    __next_pointer __detach() _NOEXCEPT;
1419
1420    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
1421    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
1422};
1423
1424template <class _Tp, class _Hash, class _Equal, class _Alloc>
1425inline
1426__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table()
1427    _NOEXCEPT_(
1428        is_nothrow_default_constructible<__bucket_list>::value &&
1429        is_nothrow_default_constructible<__first_node>::value &&
1430        is_nothrow_default_constructible<__node_allocator>::value &&
1431        is_nothrow_default_constructible<hasher>::value &&
1432        is_nothrow_default_constructible<key_equal>::value)
1433    : __p2_(0, __default_init_tag()),
1434      __p3_(1.0f, __default_init_tag())
1435{
1436}
1437
1438template <class _Tp, class _Hash, class _Equal, class _Alloc>
1439inline
1440__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
1441                                                       const key_equal& __eql)
1442    : __bucket_list_(nullptr, __bucket_list_deleter()),
1443      __p1_(),
1444      __p2_(0, __hf),
1445      __p3_(1.0f, __eql)
1446{
1447}
1448
1449template <class _Tp, class _Hash, class _Equal, class _Alloc>
1450__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
1451                                                       const key_equal& __eql,
1452                                                       const allocator_type& __a)
1453    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1454      __p1_(__default_init_tag(), __node_allocator(__a)),
1455      __p2_(0, __hf),
1456      __p3_(1.0f, __eql)
1457{
1458}
1459
1460template <class _Tp, class _Hash, class _Equal, class _Alloc>
1461__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const allocator_type& __a)
1462    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1463      __p1_(__default_init_tag(), __node_allocator(__a)),
1464      __p2_(0, __default_init_tag()),
1465      __p3_(1.0f, __default_init_tag())
1466{
1467}
1468
1469template <class _Tp, class _Hash, class _Equal, class _Alloc>
1470__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u)
1471    : __bucket_list_(nullptr,
1472          __bucket_list_deleter(allocator_traits<__pointer_allocator>::
1473              select_on_container_copy_construction(
1474                  __u.__bucket_list_.get_deleter().__alloc()), 0)),
1475      __p1_(__default_init_tag(), allocator_traits<__node_allocator>::
1476          select_on_container_copy_construction(__u.__node_alloc())),
1477      __p2_(0, __u.hash_function()),
1478      __p3_(__u.__p3_)
1479{
1480}
1481
1482template <class _Tp, class _Hash, class _Equal, class _Alloc>
1483__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u,
1484                                                       const allocator_type& __a)
1485    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1486      __p1_(__default_init_tag(), __node_allocator(__a)),
1487      __p2_(0, __u.hash_function()),
1488      __p3_(__u.__p3_)
1489{
1490}
1491
1492#ifndef _LIBCPP_CXX03_LANG
1493
1494template <class _Tp, class _Hash, class _Equal, class _Alloc>
1495__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u)
1496        _NOEXCEPT_(
1497            is_nothrow_move_constructible<__bucket_list>::value &&
1498            is_nothrow_move_constructible<__first_node>::value &&
1499            is_nothrow_move_constructible<__node_allocator>::value &&
1500            is_nothrow_move_constructible<hasher>::value &&
1501            is_nothrow_move_constructible<key_equal>::value)
1502    : __bucket_list_(_VSTD::move(__u.__bucket_list_)),
1503      __p1_(_VSTD::move(__u.__p1_)),
1504      __p2_(_VSTD::move(__u.__p2_)),
1505      __p3_(_VSTD::move(__u.__p3_))
1506{
1507    if (size() > 0)
1508    {
1509        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
1510            __p1_.first().__ptr();
1511        __u.__p1_.first().__next_ = nullptr;
1512        __u.size() = 0;
1513    }
1514}
1515
1516template <class _Tp, class _Hash, class _Equal, class _Alloc>
1517__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u,
1518                                                       const allocator_type& __a)
1519    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1520      __p1_(__default_init_tag(), __node_allocator(__a)),
1521      __p2_(0, _VSTD::move(__u.hash_function())),
1522      __p3_(_VSTD::move(__u.__p3_))
1523{
1524    if (__a == allocator_type(__u.__node_alloc()))
1525    {
1526        __bucket_list_.reset(__u.__bucket_list_.release());
1527        __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
1528        __u.__bucket_list_.get_deleter().size() = 0;
1529        if (__u.size() > 0)
1530        {
1531            __p1_.first().__next_ = __u.__p1_.first().__next_;
1532            __u.__p1_.first().__next_ = nullptr;
1533            __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
1534                __p1_.first().__ptr();
1535            size() = __u.size();
1536            __u.size() = 0;
1537        }
1538    }
1539}
1540
1541#endif  // _LIBCPP_CXX03_LANG
1542
1543template <class _Tp, class _Hash, class _Equal, class _Alloc>
1544__hash_table<_Tp, _Hash, _Equal, _Alloc>::~__hash_table()
1545{
1546#if defined(_LIBCPP_CXX03_LANG)
1547    static_assert((is_copy_constructible<key_equal>::value),
1548                 "Predicate must be copy-constructible.");
1549    static_assert((is_copy_constructible<hasher>::value),
1550                 "Hasher must be copy-constructible.");
1551#endif
1552
1553    __deallocate_node(__p1_.first().__next_);
1554#if _LIBCPP_DEBUG_LEVEL == 2
1555    __get_db()->__erase_c(this);
1556#endif
1557}
1558
1559template <class _Tp, class _Hash, class _Equal, class _Alloc>
1560void
1561__hash_table<_Tp, _Hash, _Equal, _Alloc>::__copy_assign_alloc(
1562        const __hash_table& __u, true_type)
1563{
1564    if (__node_alloc() != __u.__node_alloc())
1565    {
1566        clear();
1567        __bucket_list_.reset();
1568        __bucket_list_.get_deleter().size() = 0;
1569    }
1570    __bucket_list_.get_deleter().__alloc() = __u.__bucket_list_.get_deleter().__alloc();
1571    __node_alloc() = __u.__node_alloc();
1572}
1573
1574template <class _Tp, class _Hash, class _Equal, class _Alloc>
1575__hash_table<_Tp, _Hash, _Equal, _Alloc>&
1576__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(const __hash_table& __u)
1577{
1578    if (this != &__u)
1579    {
1580        __copy_assign_alloc(__u);
1581        hash_function() = __u.hash_function();
1582        key_eq() = __u.key_eq();
1583        max_load_factor() = __u.max_load_factor();
1584        __assign_multi(__u.begin(), __u.end());
1585    }
1586    return *this;
1587}
1588
1589template <class _Tp, class _Hash, class _Equal, class _Alloc>
1590void
1591__hash_table<_Tp, _Hash, _Equal, _Alloc>::__deallocate_node(__next_pointer __np)
1592    _NOEXCEPT
1593{
1594    __node_allocator& __na = __node_alloc();
1595    while (__np != nullptr)
1596    {
1597        __next_pointer __next = __np->__next_;
1598#if _LIBCPP_DEBUG_LEVEL == 2
1599        __c_node* __c = __get_db()->__find_c_and_lock(this);
1600        for (__i_node** __p = __c->end_; __p != __c->beg_; )
1601        {
1602            --__p;
1603            iterator* __i = static_cast<iterator*>((*__p)->__i_);
1604            if (__i->__node_ == __np)
1605            {
1606                (*__p)->__c_ = nullptr;
1607                if (--__c->end_ != __p)
1608                    memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
1609            }
1610        }
1611        __get_db()->unlock();
1612#endif
1613        __node_pointer __real_np = __np->__upcast();
1614        __node_traits::destroy(__na, _NodeTypes::__get_ptr(__real_np->__value_));
1615        __node_traits::deallocate(__na, __real_np, 1);
1616        __np = __next;
1617    }
1618}
1619
1620template <class _Tp, class _Hash, class _Equal, class _Alloc>
1621typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
1622__hash_table<_Tp, _Hash, _Equal, _Alloc>::__detach() _NOEXCEPT
1623{
1624    size_type __bc = bucket_count();
1625    for (size_type __i = 0; __i < __bc; ++__i)
1626        __bucket_list_[__i] = nullptr;
1627    size() = 0;
1628    __next_pointer __cache = __p1_.first().__next_;
1629    __p1_.first().__next_ = nullptr;
1630    return __cache;
1631}
1632
1633#ifndef _LIBCPP_CXX03_LANG
1634
1635template <class _Tp, class _Hash, class _Equal, class _Alloc>
1636void
1637__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
1638        __hash_table& __u, true_type)
1639    _NOEXCEPT_(
1640        is_nothrow_move_assignable<__node_allocator>::value &&
1641        is_nothrow_move_assignable<hasher>::value &&
1642        is_nothrow_move_assignable<key_equal>::value)
1643{
1644    clear();
1645    __bucket_list_.reset(__u.__bucket_list_.release());
1646    __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
1647    __u.__bucket_list_.get_deleter().size() = 0;
1648    __move_assign_alloc(__u);
1649    size() = __u.size();
1650    hash_function() = _VSTD::move(__u.hash_function());
1651    max_load_factor() = __u.max_load_factor();
1652    key_eq() = _VSTD::move(__u.key_eq());
1653    __p1_.first().__next_ = __u.__p1_.first().__next_;
1654    if (size() > 0)
1655    {
1656        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
1657            __p1_.first().__ptr();
1658        __u.__p1_.first().__next_ = nullptr;
1659        __u.size() = 0;
1660    }
1661#if _LIBCPP_DEBUG_LEVEL == 2
1662    __get_db()->swap(this, &__u);
1663#endif
1664}
1665
1666template <class _Tp, class _Hash, class _Equal, class _Alloc>
1667void
1668__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
1669        __hash_table& __u, false_type)
1670{
1671    if (__node_alloc() == __u.__node_alloc())
1672        __move_assign(__u, true_type());
1673    else
1674    {
1675        hash_function() = _VSTD::move(__u.hash_function());
1676        key_eq() = _VSTD::move(__u.key_eq());
1677        max_load_factor() = __u.max_load_factor();
1678        if (bucket_count() != 0)
1679        {
1680            __next_pointer __cache = __detach();
1681#ifndef _LIBCPP_NO_EXCEPTIONS
1682            try
1683            {
1684#endif  // _LIBCPP_NO_EXCEPTIONS
1685                const_iterator __i = __u.begin();
1686                while (__cache != nullptr && __u.size() != 0)
1687                {
1688                    __cache->__upcast()->__value_ =
1689                        _VSTD::move(__u.remove(__i++)->__value_);
1690                    __next_pointer __next = __cache->__next_;
1691                    __node_insert_multi(__cache->__upcast());
1692                    __cache = __next;
1693                }
1694#ifndef _LIBCPP_NO_EXCEPTIONS
1695            }
1696            catch (...)
1697            {
1698                __deallocate_node(__cache);
1699                throw;
1700            }
1701#endif  // _LIBCPP_NO_EXCEPTIONS
1702            __deallocate_node(__cache);
1703        }
1704        const_iterator __i = __u.begin();
1705        while (__u.size() != 0)
1706        {
1707            __node_holder __h = __construct_node(_NodeTypes::__move(__u.remove(__i++)->__value_));
1708            __node_insert_multi(__h.get());
1709            __h.release();
1710        }
1711    }
1712}
1713
1714template <class _Tp, class _Hash, class _Equal, class _Alloc>
1715inline
1716__hash_table<_Tp, _Hash, _Equal, _Alloc>&
1717__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(__hash_table&& __u)
1718    _NOEXCEPT_(
1719        __node_traits::propagate_on_container_move_assignment::value &&
1720        is_nothrow_move_assignable<__node_allocator>::value &&
1721        is_nothrow_move_assignable<hasher>::value &&
1722        is_nothrow_move_assignable<key_equal>::value)
1723{
1724    __move_assign(__u, integral_constant<bool,
1725                  __node_traits::propagate_on_container_move_assignment::value>());
1726    return *this;
1727}
1728
1729#endif  // _LIBCPP_CXX03_LANG
1730
1731template <class _Tp, class _Hash, class _Equal, class _Alloc>
1732template <class _InputIterator>
1733void
1734__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_unique(_InputIterator __first,
1735                                                          _InputIterator __last)
1736{
1737    typedef iterator_traits<_InputIterator> _ITraits;
1738    typedef typename _ITraits::value_type _ItValueType;
1739    static_assert((is_same<_ItValueType, __container_value_type>::value),
1740                  "__assign_unique may only be called with the containers value type");
1741
1742    if (bucket_count() != 0)
1743    {
1744        __next_pointer __cache = __detach();
1745#ifndef _LIBCPP_NO_EXCEPTIONS
1746        try
1747        {
1748#endif  // _LIBCPP_NO_EXCEPTIONS
1749            for (; __cache != nullptr && __first != __last; ++__first)
1750            {
1751                __cache->__upcast()->__value_ = *__first;
1752                __next_pointer __next = __cache->__next_;
1753                __node_insert_unique(__cache->__upcast());
1754                __cache = __next;
1755            }
1756#ifndef _LIBCPP_NO_EXCEPTIONS
1757        }
1758        catch (...)
1759        {
1760            __deallocate_node(__cache);
1761            throw;
1762        }
1763#endif  // _LIBCPP_NO_EXCEPTIONS
1764        __deallocate_node(__cache);
1765    }
1766    for (; __first != __last; ++__first)
1767        __insert_unique(*__first);
1768}
1769
1770template <class _Tp, class _Hash, class _Equal, class _Alloc>
1771template <class _InputIterator>
1772void
1773__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_multi(_InputIterator __first,
1774                                                         _InputIterator __last)
1775{
1776    typedef iterator_traits<_InputIterator> _ITraits;
1777    typedef typename _ITraits::value_type _ItValueType;
1778    static_assert((is_same<_ItValueType, __container_value_type>::value ||
1779                  is_same<_ItValueType, __node_value_type>::value),
1780                  "__assign_multi may only be called with the containers value type"
1781                  " or the nodes value type");
1782    if (bucket_count() != 0)
1783    {
1784        __next_pointer __cache = __detach();
1785#ifndef _LIBCPP_NO_EXCEPTIONS
1786        try
1787        {
1788#endif  // _LIBCPP_NO_EXCEPTIONS
1789            for (; __cache != nullptr && __first != __last; ++__first)
1790            {
1791                __cache->__upcast()->__value_ = *__first;
1792                __next_pointer __next = __cache->__next_;
1793                __node_insert_multi(__cache->__upcast());
1794                __cache = __next;
1795            }
1796#ifndef _LIBCPP_NO_EXCEPTIONS
1797        }
1798        catch (...)
1799        {
1800            __deallocate_node(__cache);
1801            throw;
1802        }
1803#endif  // _LIBCPP_NO_EXCEPTIONS
1804        __deallocate_node(__cache);
1805    }
1806    for (; __first != __last; ++__first)
1807        __insert_multi(_NodeTypes::__get_value(*__first));
1808}
1809
1810template <class _Tp, class _Hash, class _Equal, class _Alloc>
1811inline
1812typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
1813__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() _NOEXCEPT
1814{
1815#if _LIBCPP_DEBUG_LEVEL == 2
1816    return iterator(__p1_.first().__next_, this);
1817#else
1818    return iterator(__p1_.first().__next_);
1819#endif
1820}
1821
1822template <class _Tp, class _Hash, class _Equal, class _Alloc>
1823inline
1824typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
1825__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() _NOEXCEPT
1826{
1827#if _LIBCPP_DEBUG_LEVEL == 2
1828    return iterator(nullptr, this);
1829#else
1830    return iterator(nullptr);
1831#endif
1832}
1833
1834template <class _Tp, class _Hash, class _Equal, class _Alloc>
1835inline
1836typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
1837__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() const _NOEXCEPT
1838{
1839#if _LIBCPP_DEBUG_LEVEL == 2
1840    return const_iterator(__p1_.first().__next_, this);
1841#else
1842    return const_iterator(__p1_.first().__next_);
1843#endif
1844}
1845
1846template <class _Tp, class _Hash, class _Equal, class _Alloc>
1847inline
1848typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
1849__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() const _NOEXCEPT
1850{
1851#if _LIBCPP_DEBUG_LEVEL == 2
1852    return const_iterator(nullptr, this);
1853#else
1854    return const_iterator(nullptr);
1855#endif
1856}
1857
1858template <class _Tp, class _Hash, class _Equal, class _Alloc>
1859void
1860__hash_table<_Tp, _Hash, _Equal, _Alloc>::clear() _NOEXCEPT
1861{
1862    if (size() > 0)
1863    {
1864        __deallocate_node(__p1_.first().__next_);
1865        __p1_.first().__next_ = nullptr;
1866        size_type __bc = bucket_count();
1867        for (size_type __i = 0; __i < __bc; ++__i)
1868            __bucket_list_[__i] = nullptr;
1869        size() = 0;
1870    }
1871}
1872
1873
1874// Prepare the container for an insertion of the value __value with the hash
1875// __hash. This does a lookup into the container to see if __value is already
1876// present, and performs a rehash if necessary. Returns a pointer to the
1877// existing element if it exists, otherwise nullptr.
1878//
1879// Note that this function does forward exceptions if key_eq() throws, and never
1880// mutates __value or actually inserts into the map.
1881template <class _Tp, class _Hash, class _Equal, class _Alloc>
1882_LIBCPP_INLINE_VISIBILITY
1883typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
1884__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique_prepare(
1885    size_t __hash, value_type& __value)
1886{
1887    size_type __bc = bucket_count();
1888
1889    if (__bc != 0)
1890    {
1891        size_t __chash = __constrain_hash(__hash, __bc);
1892        __next_pointer __ndptr = __bucket_list_[__chash];
1893        if (__ndptr != nullptr)
1894        {
1895            for (__ndptr = __ndptr->__next_; __ndptr != nullptr &&
1896                                             __constrain_hash(__ndptr->__hash(), __bc) == __chash;
1897                                                     __ndptr = __ndptr->__next_)
1898            {
1899                if (key_eq()(__ndptr->__upcast()->__value_, __value))
1900                    return __ndptr;
1901            }
1902        }
1903    }
1904    if (size()+1 > __bc * max_load_factor() || __bc == 0)
1905    {
1906        rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
1907                                     size_type(ceil(float(size() + 1) / max_load_factor()))));
1908    }
1909    return nullptr;
1910}
1911
1912// Insert the node __nd into the container by pushing it into the right bucket,
1913// and updating size(). Assumes that __nd->__hash is up-to-date, and that
1914// rehashing has already occurred and that no element with the same key exists
1915// in the map.
1916template <class _Tp, class _Hash, class _Equal, class _Alloc>
1917_LIBCPP_INLINE_VISIBILITY
1918void
1919__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique_perform(
1920    __node_pointer __nd) _NOEXCEPT
1921{
1922    size_type __bc = bucket_count();
1923    size_t __chash = __constrain_hash(__nd->__hash(), __bc);
1924    // insert_after __bucket_list_[__chash], or __first_node if bucket is null
1925    __next_pointer __pn = __bucket_list_[__chash];
1926    if (__pn == nullptr)
1927    {
1928        __pn =__p1_.first().__ptr();
1929        __nd->__next_ = __pn->__next_;
1930        __pn->__next_ = __nd->__ptr();
1931        // fix up __bucket_list_
1932        __bucket_list_[__chash] = __pn;
1933        if (__nd->__next_ != nullptr)
1934            __bucket_list_[__constrain_hash(__nd->__next_->__hash(), __bc)] = __nd->__ptr();
1935    }
1936    else
1937    {
1938        __nd->__next_ = __pn->__next_;
1939        __pn->__next_ = __nd->__ptr();
1940    }
1941    ++size();
1942}
1943
1944template <class _Tp, class _Hash, class _Equal, class _Alloc>
1945pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
1946__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique(__node_pointer __nd)
1947{
1948    __nd->__hash_ = hash_function()(__nd->__value_);
1949    __next_pointer __existing_node =
1950        __node_insert_unique_prepare(__nd->__hash(), __nd->__value_);
1951
1952    // Insert the node, unless it already exists in the container.
1953    bool __inserted = false;
1954    if (__existing_node == nullptr)
1955    {
1956        __node_insert_unique_perform(__nd);
1957        __existing_node = __nd->__ptr();
1958        __inserted = true;
1959    }
1960#if _LIBCPP_DEBUG_LEVEL == 2
1961    return pair<iterator, bool>(iterator(__existing_node, this), __inserted);
1962#else
1963    return pair<iterator, bool>(iterator(__existing_node), __inserted);
1964#endif
1965}
1966
1967// Prepare the container for an insertion of the value __cp_val with the hash
1968// __cp_hash. This does a lookup into the container to see if __cp_value is
1969// already present, and performs a rehash if necessary. Returns a pointer to the
1970// last occurance of __cp_val in the map.
1971//
1972// Note that this function does forward exceptions if key_eq() throws, and never
1973// mutates __value or actually inserts into the map.
1974template <class _Tp, class _Hash, class _Equal, class _Alloc>
1975typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
1976__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi_prepare(
1977    size_t __cp_hash, value_type& __cp_val)
1978{
1979    size_type __bc = bucket_count();
1980    if (size()+1 > __bc * max_load_factor() || __bc == 0)
1981    {
1982        rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
1983                       size_type(ceil(float(size() + 1) / max_load_factor()))));
1984        __bc = bucket_count();
1985    }
1986    size_t __chash = __constrain_hash(__cp_hash, __bc);
1987    __next_pointer __pn = __bucket_list_[__chash];
1988    if (__pn != nullptr)
1989    {
1990        for (bool __found = false; __pn->__next_ != nullptr &&
1991                                   __constrain_hash(__pn->__next_->__hash(), __bc) == __chash;
1992                                                           __pn = __pn->__next_)
1993        {
1994            //      __found    key_eq()     action
1995            //      false       false       loop
1996            //      true        true        loop
1997            //      false       true        set __found to true
1998            //      true        false       break
1999            if (__found != (__pn->__next_->__hash() == __cp_hash &&
2000                            key_eq()(__pn->__next_->__upcast()->__value_, __cp_val)))
2001            {
2002                if (!__found)
2003                    __found = true;
2004                else
2005                    break;
2006            }
2007        }
2008    }
2009    return __pn;
2010}
2011
2012// Insert the node __cp into the container after __pn (which is the last node in
2013// the bucket that compares equal to __cp). Rehashing, and checking for
2014// uniqueness has already been performed (in __node_insert_multi_prepare), so
2015// all we need to do is update the bucket and size(). Assumes that __cp->__hash
2016// is up-to-date.
2017template <class _Tp, class _Hash, class _Equal, class _Alloc>
2018void
2019__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi_perform(
2020    __node_pointer __cp, __next_pointer __pn) _NOEXCEPT
2021{
2022    size_type __bc = bucket_count();
2023    size_t __chash = __constrain_hash(__cp->__hash_, __bc);
2024    if (__pn == nullptr)
2025    {
2026        __pn =__p1_.first().__ptr();
2027        __cp->__next_ = __pn->__next_;
2028        __pn->__next_ = __cp->__ptr();
2029        // fix up __bucket_list_
2030        __bucket_list_[__chash] = __pn;
2031        if (__cp->__next_ != nullptr)
2032            __bucket_list_[__constrain_hash(__cp->__next_->__hash(), __bc)]
2033                = __cp->__ptr();
2034    }
2035    else
2036    {
2037        __cp->__next_ = __pn->__next_;
2038        __pn->__next_ = __cp->__ptr();
2039        if (__cp->__next_ != nullptr)
2040        {
2041            size_t __nhash = __constrain_hash(__cp->__next_->__hash(), __bc);
2042            if (__nhash != __chash)
2043                __bucket_list_[__nhash] = __cp->__ptr();
2044        }
2045    }
2046    ++size();
2047}
2048
2049
2050template <class _Tp, class _Hash, class _Equal, class _Alloc>
2051typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2052__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(__node_pointer __cp)
2053{
2054    __cp->__hash_ = hash_function()(__cp->__value_);
2055    __next_pointer __pn = __node_insert_multi_prepare(__cp->__hash(), __cp->__value_);
2056    __node_insert_multi_perform(__cp, __pn);
2057
2058#if _LIBCPP_DEBUG_LEVEL == 2
2059    return iterator(__cp->__ptr(), this);
2060#else
2061    return iterator(__cp->__ptr());
2062#endif
2063}
2064
2065template <class _Tp, class _Hash, class _Equal, class _Alloc>
2066typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2067__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(
2068        const_iterator __p, __node_pointer __cp)
2069{
2070#if _LIBCPP_DEBUG_LEVEL == 2
2071    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
2072        "unordered container::emplace_hint(const_iterator, args...) called with an iterator not"
2073        " referring to this unordered container");
2074#endif
2075    if (__p != end() && key_eq()(*__p, __cp->__value_))
2076    {
2077        __next_pointer __np = __p.__node_;
2078        __cp->__hash_ = __np->__hash();
2079        size_type __bc = bucket_count();
2080        if (size()+1 > __bc * max_load_factor() || __bc == 0)
2081        {
2082            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
2083                           size_type(ceil(float(size() + 1) / max_load_factor()))));
2084            __bc = bucket_count();
2085        }
2086        size_t __chash = __constrain_hash(__cp->__hash_, __bc);
2087        __next_pointer __pp = __bucket_list_[__chash];
2088        while (__pp->__next_ != __np)
2089            __pp = __pp->__next_;
2090        __cp->__next_ = __np;
2091        __pp->__next_ = static_cast<__next_pointer>(__cp);
2092        ++size();
2093#if _LIBCPP_DEBUG_LEVEL == 2
2094        return iterator(static_cast<__next_pointer>(__cp), this);
2095#else
2096        return iterator(static_cast<__next_pointer>(__cp));
2097#endif
2098    }
2099    return __node_insert_multi(__cp);
2100}
2101
2102
2103
2104#ifndef _LIBCPP_CXX03_LANG
2105template <class _Tp, class _Hash, class _Equal, class _Alloc>
2106template <class _Key, class ..._Args>
2107pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
2108__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_key_args(_Key const& __k, _Args&&... __args)
2109#else
2110template <class _Tp, class _Hash, class _Equal, class _Alloc>
2111template <class _Key, class _Args>
2112pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
2113__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_key_args(_Key const& __k, _Args& __args)
2114#endif
2115{
2116
2117    size_t __hash = hash_function()(__k);
2118    size_type __bc = bucket_count();
2119    bool __inserted = false;
2120    __next_pointer __nd;
2121    size_t __chash;
2122    if (__bc != 0)
2123    {
2124        __chash = __constrain_hash(__hash, __bc);
2125        __nd = __bucket_list_[__chash];
2126        if (__nd != nullptr)
2127        {
2128            for (__nd = __nd->__next_; __nd != nullptr &&
2129                (__nd->__hash() == __hash || __constrain_hash(__nd->__hash(), __bc) == __chash);
2130                                                           __nd = __nd->__next_)
2131            {
2132                if (key_eq()(__nd->__upcast()->__value_, __k))
2133                    goto __done;
2134            }
2135        }
2136    }
2137    {
2138#ifndef _LIBCPP_CXX03_LANG
2139        __node_holder __h = __construct_node_hash(__hash, _VSTD::forward<_Args>(__args)...);
2140#else
2141        __node_holder __h = __construct_node_hash(__hash, __args);
2142#endif
2143        if (size()+1 > __bc * max_load_factor() || __bc == 0)
2144        {
2145            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
2146                           size_type(ceil(float(size() + 1) / max_load_factor()))));
2147            __bc = bucket_count();
2148            __chash = __constrain_hash(__hash, __bc);
2149        }
2150        // insert_after __bucket_list_[__chash], or __first_node if bucket is null
2151        __next_pointer __pn = __bucket_list_[__chash];
2152        if (__pn == nullptr)
2153        {
2154            __pn = __p1_.first().__ptr();
2155            __h->__next_ = __pn->__next_;
2156            __pn->__next_ = __h.get()->__ptr();
2157            // fix up __bucket_list_
2158            __bucket_list_[__chash] = __pn;
2159            if (__h->__next_ != nullptr)
2160                __bucket_list_[__constrain_hash(__h->__next_->__hash(), __bc)]
2161                    = __h.get()->__ptr();
2162        }
2163        else
2164        {
2165            __h->__next_ = __pn->__next_;
2166            __pn->__next_ = static_cast<__next_pointer>(__h.get());
2167        }
2168        __nd = static_cast<__next_pointer>(__h.release());
2169        // increment size
2170        ++size();
2171        __inserted = true;
2172    }
2173__done:
2174#if _LIBCPP_DEBUG_LEVEL == 2
2175    return pair<iterator, bool>(iterator(__nd, this), __inserted);
2176#else
2177    return pair<iterator, bool>(iterator(__nd), __inserted);
2178#endif
2179}
2180
2181#ifndef _LIBCPP_CXX03_LANG
2182
2183template <class _Tp, class _Hash, class _Equal, class _Alloc>
2184template <class... _Args>
2185pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
2186__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_impl(_Args&&... __args)
2187{
2188    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2189    pair<iterator, bool> __r = __node_insert_unique(__h.get());
2190    if (__r.second)
2191        __h.release();
2192    return __r;
2193}
2194
2195template <class _Tp, class _Hash, class _Equal, class _Alloc>
2196template <class... _Args>
2197typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2198__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_multi(_Args&&... __args)
2199{
2200    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2201    iterator __r = __node_insert_multi(__h.get());
2202    __h.release();
2203    return __r;
2204}
2205
2206template <class _Tp, class _Hash, class _Equal, class _Alloc>
2207template <class... _Args>
2208typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2209__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_hint_multi(
2210        const_iterator __p, _Args&&... __args)
2211{
2212#if _LIBCPP_DEBUG_LEVEL == 2
2213    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
2214        "unordered container::emplace_hint(const_iterator, args...) called with an iterator not"
2215        " referring to this unordered container");
2216#endif
2217    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2218    iterator __r = __node_insert_multi(__p, __h.get());
2219    __h.release();
2220    return __r;
2221}
2222
2223#else // _LIBCPP_CXX03_LANG
2224
2225template <class _Tp, class _Hash, class _Equal, class _Alloc>
2226typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2227__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_multi(const __container_value_type& __x)
2228{
2229    __node_holder __h = __construct_node(__x);
2230    iterator __r = __node_insert_multi(__h.get());
2231    __h.release();
2232    return __r;
2233}
2234
2235template <class _Tp, class _Hash, class _Equal, class _Alloc>
2236typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2237__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_multi(const_iterator __p,
2238                                                         const __container_value_type& __x)
2239{
2240#if _LIBCPP_DEBUG_LEVEL == 2
2241    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
2242        "unordered container::insert(const_iterator, lvalue) called with an iterator not"
2243        " referring to this unordered container");
2244#endif
2245    __node_holder __h = __construct_node(__x);
2246    iterator __r = __node_insert_multi(__p, __h.get());
2247    __h.release();
2248    return __r;
2249}
2250
2251#endif  // _LIBCPP_CXX03_LANG
2252
2253#if _LIBCPP_STD_VER > 14
2254template <class _Tp, class _Hash, class _Equal, class _Alloc>
2255template <class _NodeHandle, class _InsertReturnType>
2256_LIBCPP_INLINE_VISIBILITY
2257_InsertReturnType
2258__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_unique(
2259    _NodeHandle&& __nh)
2260{
2261    if (__nh.empty())
2262        return _InsertReturnType{end(), false, _NodeHandle()};
2263    pair<iterator, bool> __result = __node_insert_unique(__nh.__ptr_);
2264    if (__result.second)
2265        __nh.__release_ptr();
2266    return _InsertReturnType{__result.first, __result.second, _VSTD::move(__nh)};
2267}
2268
2269template <class _Tp, class _Hash, class _Equal, class _Alloc>
2270template <class _NodeHandle>
2271_LIBCPP_INLINE_VISIBILITY
2272typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2273__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_unique(
2274    const_iterator, _NodeHandle&& __nh)
2275{
2276    if (__nh.empty())
2277        return end();
2278    pair<iterator, bool> __result = __node_insert_unique(__nh.__ptr_);
2279    if (__result.second)
2280        __nh.__release_ptr();
2281    return __result.first;
2282}
2283
2284template <class _Tp, class _Hash, class _Equal, class _Alloc>
2285template <class _NodeHandle>
2286_LIBCPP_INLINE_VISIBILITY
2287_NodeHandle
2288__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_extract(
2289    key_type const& __key)
2290{
2291    iterator __i = find(__key);
2292    if (__i == end())
2293        return _NodeHandle();
2294    return __node_handle_extract<_NodeHandle>(__i);
2295}
2296
2297template <class _Tp, class _Hash, class _Equal, class _Alloc>
2298template <class _NodeHandle>
2299_LIBCPP_INLINE_VISIBILITY
2300_NodeHandle
2301__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_extract(
2302    const_iterator __p)
2303{
2304    allocator_type __alloc(__node_alloc());
2305    return _NodeHandle(remove(__p).release(), __alloc);
2306}
2307
2308template <class _Tp, class _Hash, class _Equal, class _Alloc>
2309template <class _Table>
2310_LIBCPP_INLINE_VISIBILITY
2311void
2312__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_merge_unique(
2313    _Table& __source)
2314{
2315    static_assert(is_same<__node, typename _Table::__node>::value, "");
2316
2317    for (typename _Table::iterator __it = __source.begin();
2318         __it != __source.end();)
2319    {
2320        __node_pointer __src_ptr = __it.__node_->__upcast();
2321        size_t __hash = hash_function()(__src_ptr->__value_);
2322        __next_pointer __existing_node =
2323            __node_insert_unique_prepare(__hash, __src_ptr->__value_);
2324        auto __prev_iter = __it++;
2325        if (__existing_node == nullptr)
2326        {
2327            (void)__source.remove(__prev_iter).release();
2328            __src_ptr->__hash_ = __hash;
2329            __node_insert_unique_perform(__src_ptr);
2330        }
2331    }
2332}
2333
2334template <class _Tp, class _Hash, class _Equal, class _Alloc>
2335template <class _NodeHandle>
2336_LIBCPP_INLINE_VISIBILITY
2337typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2338__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_multi(
2339    _NodeHandle&& __nh)
2340{
2341    if (__nh.empty())
2342        return end();
2343    iterator __result = __node_insert_multi(__nh.__ptr_);
2344    __nh.__release_ptr();
2345    return __result;
2346}
2347
2348template <class _Tp, class _Hash, class _Equal, class _Alloc>
2349template <class _NodeHandle>
2350_LIBCPP_INLINE_VISIBILITY
2351typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2352__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_multi(
2353    const_iterator __hint, _NodeHandle&& __nh)
2354{
2355    if (__nh.empty())
2356        return end();
2357    iterator __result = __node_insert_multi(__hint, __nh.__ptr_);
2358    __nh.__release_ptr();
2359    return __result;
2360}
2361
2362template <class _Tp, class _Hash, class _Equal, class _Alloc>
2363template <class _Table>
2364_LIBCPP_INLINE_VISIBILITY
2365void
2366__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_merge_multi(
2367    _Table& __source)
2368{
2369    static_assert(is_same<typename _Table::__node, __node>::value, "");
2370
2371    for (typename _Table::iterator __it = __source.begin();
2372         __it != __source.end();)
2373    {
2374        __node_pointer __src_ptr = __it.__node_->__upcast();
2375        size_t __src_hash = hash_function()(__src_ptr->__value_);
2376        __next_pointer __pn =
2377            __node_insert_multi_prepare(__src_hash, __src_ptr->__value_);
2378        (void)__source.remove(__it++).release();
2379        __src_ptr->__hash_ = __src_hash;
2380        __node_insert_multi_perform(__src_ptr, __pn);
2381    }
2382}
2383#endif  // _LIBCPP_STD_VER > 14
2384
2385template <class _Tp, class _Hash, class _Equal, class _Alloc>
2386void
2387__hash_table<_Tp, _Hash, _Equal, _Alloc>::rehash(size_type __n)
2388_LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
2389{
2390    if (__n == 1)
2391        __n = 2;
2392    else if (__n & (__n - 1))
2393        __n = __next_prime(__n);
2394    size_type __bc = bucket_count();
2395    if (__n > __bc)
2396        __rehash(__n);
2397    else if (__n < __bc)
2398    {
2399        __n = _VSTD::max<size_type>
2400              (
2401                  __n,
2402                  __is_hash_power2(__bc) ? __next_hash_pow2(size_t(ceil(float(size()) / max_load_factor()))) :
2403                                           __next_prime(size_t(ceil(float(size()) / max_load_factor())))
2404              );
2405        if (__n < __bc)
2406            __rehash(__n);
2407    }
2408}
2409
2410template <class _Tp, class _Hash, class _Equal, class _Alloc>
2411void
2412__hash_table<_Tp, _Hash, _Equal, _Alloc>::__rehash(size_type __nbc)
2413{
2414#if _LIBCPP_DEBUG_LEVEL == 2
2415    __get_db()->__invalidate_all(this);
2416#endif
2417    __pointer_allocator& __npa = __bucket_list_.get_deleter().__alloc();
2418    __bucket_list_.reset(__nbc > 0 ?
2419                      __pointer_alloc_traits::allocate(__npa, __nbc) : nullptr);
2420    __bucket_list_.get_deleter().size() = __nbc;
2421    if (__nbc > 0)
2422    {
2423        for (size_type __i = 0; __i < __nbc; ++__i)
2424            __bucket_list_[__i] = nullptr;
2425        __next_pointer __pp = __p1_.first().__ptr();
2426        __next_pointer __cp = __pp->__next_;
2427        if (__cp != nullptr)
2428        {
2429            size_type __chash = __constrain_hash(__cp->__hash(), __nbc);
2430            __bucket_list_[__chash] = __pp;
2431            size_type __phash = __chash;
2432            for (__pp = __cp, __cp = __cp->__next_; __cp != nullptr;
2433                                                           __cp = __pp->__next_)
2434            {
2435                __chash = __constrain_hash(__cp->__hash(), __nbc);
2436                if (__chash == __phash)
2437                    __pp = __cp;
2438                else
2439                {
2440                    if (__bucket_list_[__chash] == nullptr)
2441                    {
2442                        __bucket_list_[__chash] = __pp;
2443                        __pp = __cp;
2444                        __phash = __chash;
2445                    }
2446                    else
2447                    {
2448                        __next_pointer __np = __cp;
2449                        for (; __np->__next_ != nullptr &&
2450                               key_eq()(__cp->__upcast()->__value_,
2451                                        __np->__next_->__upcast()->__value_);
2452                                                           __np = __np->__next_)
2453                            ;
2454                        __pp->__next_ = __np->__next_;
2455                        __np->__next_ = __bucket_list_[__chash]->__next_;
2456                        __bucket_list_[__chash]->__next_ = __cp;
2457
2458                    }
2459                }
2460            }
2461        }
2462    }
2463}
2464
2465template <class _Tp, class _Hash, class _Equal, class _Alloc>
2466template <class _Key>
2467typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2468__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k)
2469{
2470    size_t __hash = hash_function()(__k);
2471    size_type __bc = bucket_count();
2472    if (__bc != 0)
2473    {
2474        size_t __chash = __constrain_hash(__hash, __bc);
2475        __next_pointer __nd = __bucket_list_[__chash];
2476        if (__nd != nullptr)
2477        {
2478            for (__nd = __nd->__next_; __nd != nullptr &&
2479                (__nd->__hash() == __hash
2480                  || __constrain_hash(__nd->__hash(), __bc) == __chash);
2481                                                           __nd = __nd->__next_)
2482            {
2483                if ((__nd->__hash() == __hash)
2484                    && key_eq()(__nd->__upcast()->__value_, __k))
2485#if _LIBCPP_DEBUG_LEVEL == 2
2486                    return iterator(__nd, this);
2487#else
2488                    return iterator(__nd);
2489#endif
2490            }
2491        }
2492    }
2493    return end();
2494}
2495
2496template <class _Tp, class _Hash, class _Equal, class _Alloc>
2497template <class _Key>
2498typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
2499__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k) const
2500{
2501    size_t __hash = hash_function()(__k);
2502    size_type __bc = bucket_count();
2503    if (__bc != 0)
2504    {
2505        size_t __chash = __constrain_hash(__hash, __bc);
2506        __next_pointer __nd = __bucket_list_[__chash];
2507        if (__nd != nullptr)
2508        {
2509            for (__nd = __nd->__next_; __nd != nullptr &&
2510                (__hash == __nd->__hash()
2511                    || __constrain_hash(__nd->__hash(), __bc) == __chash);
2512                                                           __nd = __nd->__next_)
2513            {
2514                if ((__nd->__hash() == __hash)
2515                    && key_eq()(__nd->__upcast()->__value_, __k))
2516#if _LIBCPP_DEBUG_LEVEL == 2
2517                    return const_iterator(__nd, this);
2518#else
2519                    return const_iterator(__nd);
2520#endif
2521            }
2522        }
2523
2524    }
2525    return end();
2526}
2527
2528#ifndef _LIBCPP_CXX03_LANG
2529
2530template <class _Tp, class _Hash, class _Equal, class _Alloc>
2531template <class ..._Args>
2532typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
2533__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(_Args&& ...__args)
2534{
2535    static_assert(!__is_hash_value_type<_Args...>::value,
2536                  "Construct cannot be called with a hash value type");
2537    __node_allocator& __na = __node_alloc();
2538    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
2539    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), _VSTD::forward<_Args>(__args)...);
2540    __h.get_deleter().__value_constructed = true;
2541    __h->__hash_ = hash_function()(__h->__value_);
2542    __h->__next_ = nullptr;
2543    return __h;
2544}
2545
2546template <class _Tp, class _Hash, class _Equal, class _Alloc>
2547template <class _First, class ..._Rest>
2548typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
2549__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node_hash(
2550    size_t __hash, _First&& __f, _Rest&& ...__rest)
2551{
2552    static_assert(!__is_hash_value_type<_First, _Rest...>::value,
2553                  "Construct cannot be called with a hash value type");
2554    __node_allocator& __na = __node_alloc();
2555    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
2556    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_),
2557                             _VSTD::forward<_First>(__f),
2558                             _VSTD::forward<_Rest>(__rest)...);
2559    __h.get_deleter().__value_constructed = true;
2560    __h->__hash_ = __hash;
2561    __h->__next_ = nullptr;
2562    return __h;
2563}
2564
2565#else  // _LIBCPP_CXX03_LANG
2566
2567template <class _Tp, class _Hash, class _Equal, class _Alloc>
2568typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
2569__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(const __container_value_type& __v)
2570{
2571    __node_allocator& __na = __node_alloc();
2572    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
2573    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), __v);
2574    __h.get_deleter().__value_constructed = true;
2575    __h->__hash_ = hash_function()(__h->__value_);
2576    __h->__next_ = nullptr;
2577    return __h;
2578}
2579
2580template <class _Tp, class _Hash, class _Equal, class _Alloc>
2581typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
2582__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node_hash(size_t __hash,
2583                                                                const __container_value_type& __v)
2584{
2585    __node_allocator& __na = __node_alloc();
2586    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
2587    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), __v);
2588    __h.get_deleter().__value_constructed = true;
2589    __h->__hash_ = __hash;
2590    __h->__next_ = nullptr;
2591    return __h;
2592}
2593
2594#endif  // _LIBCPP_CXX03_LANG
2595
2596template <class _Tp, class _Hash, class _Equal, class _Alloc>
2597typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2598__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __p)
2599{
2600    __next_pointer __np = __p.__node_;
2601#if _LIBCPP_DEBUG_LEVEL == 2
2602    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
2603        "unordered container erase(iterator) called with an iterator not"
2604        " referring to this container");
2605    _LIBCPP_ASSERT(__p != end(),
2606        "unordered container erase(iterator) called with a non-dereferenceable iterator");
2607    iterator __r(__np, this);
2608#else
2609    iterator __r(__np);
2610#endif
2611    ++__r;
2612    remove(__p);
2613    return __r;
2614}
2615
2616template <class _Tp, class _Hash, class _Equal, class _Alloc>
2617typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2618__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __first,
2619                                                const_iterator __last)
2620{
2621#if _LIBCPP_DEBUG_LEVEL == 2
2622    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__first) == this,
2623        "unodered container::erase(iterator, iterator) called with an iterator not"
2624        " referring to this unodered container");
2625    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__last) == this,
2626        "unodered container::erase(iterator, iterator) called with an iterator not"
2627        " referring to this unodered container");
2628#endif
2629    for (const_iterator __p = __first; __first != __last; __p = __first)
2630    {
2631        ++__first;
2632        erase(__p);
2633    }
2634    __next_pointer __np = __last.__node_;
2635#if _LIBCPP_DEBUG_LEVEL == 2
2636    return iterator (__np, this);
2637#else
2638    return iterator (__np);
2639#endif
2640}
2641
2642template <class _Tp, class _Hash, class _Equal, class _Alloc>
2643template <class _Key>
2644typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2645__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_unique(const _Key& __k)
2646{
2647    iterator __i = find(__k);
2648    if (__i == end())
2649        return 0;
2650    erase(__i);
2651    return 1;
2652}
2653
2654template <class _Tp, class _Hash, class _Equal, class _Alloc>
2655template <class _Key>
2656typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2657__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_multi(const _Key& __k)
2658{
2659    size_type __r = 0;
2660    iterator __i = find(__k);
2661    if (__i != end())
2662    {
2663        iterator __e = end();
2664        do
2665        {
2666            erase(__i++);
2667            ++__r;
2668        } while (__i != __e && key_eq()(*__i, __k));
2669    }
2670    return __r;
2671}
2672
2673template <class _Tp, class _Hash, class _Equal, class _Alloc>
2674typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
2675__hash_table<_Tp, _Hash, _Equal, _Alloc>::remove(const_iterator __p) _NOEXCEPT
2676{
2677    // current node
2678    __next_pointer __cn = __p.__node_;
2679    size_type __bc = bucket_count();
2680    size_t __chash = __constrain_hash(__cn->__hash(), __bc);
2681    // find previous node
2682    __next_pointer __pn = __bucket_list_[__chash];
2683    for (; __pn->__next_ != __cn; __pn = __pn->__next_)
2684        ;
2685    // Fix up __bucket_list_
2686        // if __pn is not in same bucket (before begin is not in same bucket) &&
2687        //    if __cn->__next_ is not in same bucket (nullptr is not in same bucket)
2688    if (__pn == __p1_.first().__ptr()
2689            || __constrain_hash(__pn->__hash(), __bc) != __chash)
2690    {
2691        if (__cn->__next_ == nullptr
2692            || __constrain_hash(__cn->__next_->__hash(), __bc) != __chash)
2693            __bucket_list_[__chash] = nullptr;
2694    }
2695        // if __cn->__next_ is not in same bucket (nullptr is in same bucket)
2696    if (__cn->__next_ != nullptr)
2697    {
2698        size_t __nhash = __constrain_hash(__cn->__next_->__hash(), __bc);
2699        if (__nhash != __chash)
2700            __bucket_list_[__nhash] = __pn;
2701    }
2702    // remove __cn
2703    __pn->__next_ = __cn->__next_;
2704    __cn->__next_ = nullptr;
2705    --size();
2706#if _LIBCPP_DEBUG_LEVEL == 2
2707    __c_node* __c = __get_db()->__find_c_and_lock(this);
2708    for (__i_node** __dp = __c->end_; __dp != __c->beg_; )
2709    {
2710        --__dp;
2711        iterator* __i = static_cast<iterator*>((*__dp)->__i_);
2712        if (__i->__node_ == __cn)
2713        {
2714            (*__dp)->__c_ = nullptr;
2715            if (--__c->end_ != __dp)
2716                memmove(__dp, __dp+1, (__c->end_ - __dp)*sizeof(__i_node*));
2717        }
2718    }
2719    __get_db()->unlock();
2720#endif
2721    return __node_holder(__cn->__upcast(), _Dp(__node_alloc(), true));
2722}
2723
2724template <class _Tp, class _Hash, class _Equal, class _Alloc>
2725template <class _Key>
2726inline
2727typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2728__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_unique(const _Key& __k) const
2729{
2730    return static_cast<size_type>(find(__k) != end());
2731}
2732
2733template <class _Tp, class _Hash, class _Equal, class _Alloc>
2734template <class _Key>
2735typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2736__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_multi(const _Key& __k) const
2737{
2738    size_type __r = 0;
2739    const_iterator __i = find(__k);
2740    if (__i != end())
2741    {
2742        const_iterator __e = end();
2743        do
2744        {
2745            ++__i;
2746            ++__r;
2747        } while (__i != __e && key_eq()(*__i, __k));
2748    }
2749    return __r;
2750}
2751
2752template <class _Tp, class _Hash, class _Equal, class _Alloc>
2753template <class _Key>
2754pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
2755     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
2756__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
2757        const _Key& __k)
2758{
2759    iterator __i = find(__k);
2760    iterator __j = __i;
2761    if (__i != end())
2762        ++__j;
2763    return pair<iterator, iterator>(__i, __j);
2764}
2765
2766template <class _Tp, class _Hash, class _Equal, class _Alloc>
2767template <class _Key>
2768pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
2769     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
2770__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
2771        const _Key& __k) const
2772{
2773    const_iterator __i = find(__k);
2774    const_iterator __j = __i;
2775    if (__i != end())
2776        ++__j;
2777    return pair<const_iterator, const_iterator>(__i, __j);
2778}
2779
2780template <class _Tp, class _Hash, class _Equal, class _Alloc>
2781template <class _Key>
2782pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
2783     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
2784__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
2785        const _Key& __k)
2786{
2787    iterator __i = find(__k);
2788    iterator __j = __i;
2789    if (__i != end())
2790    {
2791        iterator __e = end();
2792        do
2793        {
2794            ++__j;
2795        } while (__j != __e && key_eq()(*__j, __k));
2796    }
2797    return pair<iterator, iterator>(__i, __j);
2798}
2799
2800template <class _Tp, class _Hash, class _Equal, class _Alloc>
2801template <class _Key>
2802pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
2803     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
2804__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
2805        const _Key& __k) const
2806{
2807    const_iterator __i = find(__k);
2808    const_iterator __j = __i;
2809    if (__i != end())
2810    {
2811        const_iterator __e = end();
2812        do
2813        {
2814            ++__j;
2815        } while (__j != __e && key_eq()(*__j, __k));
2816    }
2817    return pair<const_iterator, const_iterator>(__i, __j);
2818}
2819
2820template <class _Tp, class _Hash, class _Equal, class _Alloc>
2821void
2822__hash_table<_Tp, _Hash, _Equal, _Alloc>::swap(__hash_table& __u)
2823#if _LIBCPP_STD_VER <= 11
2824    _NOEXCEPT_(
2825        __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
2826        && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
2827              || __is_nothrow_swappable<__pointer_allocator>::value)
2828        && (!__node_traits::propagate_on_container_swap::value
2829              || __is_nothrow_swappable<__node_allocator>::value)
2830            )
2831#else
2832  _NOEXCEPT_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value)
2833#endif
2834{
2835    _LIBCPP_ASSERT(__node_traits::propagate_on_container_swap::value ||
2836                   this->__node_alloc() == __u.__node_alloc(),
2837                   "list::swap: Either propagate_on_container_swap must be true"
2838                   " or the allocators must compare equal");
2839    {
2840    __node_pointer_pointer __npp = __bucket_list_.release();
2841    __bucket_list_.reset(__u.__bucket_list_.release());
2842    __u.__bucket_list_.reset(__npp);
2843    }
2844    _VSTD::swap(__bucket_list_.get_deleter().size(), __u.__bucket_list_.get_deleter().size());
2845    __swap_allocator(__bucket_list_.get_deleter().__alloc(),
2846             __u.__bucket_list_.get_deleter().__alloc());
2847    __swap_allocator(__node_alloc(), __u.__node_alloc());
2848    _VSTD::swap(__p1_.first().__next_, __u.__p1_.first().__next_);
2849    __p2_.swap(__u.__p2_);
2850    __p3_.swap(__u.__p3_);
2851    if (size() > 0)
2852        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
2853            __p1_.first().__ptr();
2854    if (__u.size() > 0)
2855        __u.__bucket_list_[__constrain_hash(__u.__p1_.first().__next_->__hash(), __u.bucket_count())] =
2856            __u.__p1_.first().__ptr();
2857#if _LIBCPP_DEBUG_LEVEL == 2
2858    __get_db()->swap(this, &__u);
2859#endif
2860}
2861
2862template <class _Tp, class _Hash, class _Equal, class _Alloc>
2863typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2864__hash_table<_Tp, _Hash, _Equal, _Alloc>::bucket_size(size_type __n) const
2865{
2866    _LIBCPP_ASSERT(__n < bucket_count(),
2867        "unordered container::bucket_size(n) called with n >= bucket_count()");
2868    __next_pointer __np = __bucket_list_[__n];
2869    size_type __bc = bucket_count();
2870    size_type __r = 0;
2871    if (__np != nullptr)
2872    {
2873        for (__np = __np->__next_; __np != nullptr &&
2874                                   __constrain_hash(__np->__hash(), __bc) == __n;
2875                                                    __np = __np->__next_, ++__r)
2876            ;
2877    }
2878    return __r;
2879}
2880
2881template <class _Tp, class _Hash, class _Equal, class _Alloc>
2882inline _LIBCPP_INLINE_VISIBILITY
2883void
2884swap(__hash_table<_Tp, _Hash, _Equal, _Alloc>& __x,
2885     __hash_table<_Tp, _Hash, _Equal, _Alloc>& __y)
2886    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
2887{
2888    __x.swap(__y);
2889}
2890
2891#if _LIBCPP_DEBUG_LEVEL == 2
2892
2893template <class _Tp, class _Hash, class _Equal, class _Alloc>
2894bool
2895__hash_table<_Tp, _Hash, _Equal, _Alloc>::__dereferenceable(const const_iterator* __i) const
2896{
2897    return __i->__node_ != nullptr;
2898}
2899
2900template <class _Tp, class _Hash, class _Equal, class _Alloc>
2901bool
2902__hash_table<_Tp, _Hash, _Equal, _Alloc>::__decrementable(const const_iterator*) const
2903{
2904    return false;
2905}
2906
2907template <class _Tp, class _Hash, class _Equal, class _Alloc>
2908bool
2909__hash_table<_Tp, _Hash, _Equal, _Alloc>::__addable(const const_iterator*, ptrdiff_t) const
2910{
2911    return false;
2912}
2913
2914template <class _Tp, class _Hash, class _Equal, class _Alloc>
2915bool
2916__hash_table<_Tp, _Hash, _Equal, _Alloc>::__subscriptable(const const_iterator*, ptrdiff_t) const
2917{
2918    return false;
2919}
2920
2921#endif  // _LIBCPP_DEBUG_LEVEL == 2
2922
2923_LIBCPP_END_NAMESPACE_STD
2924
2925_LIBCPP_POP_MACROS
2926
2927#endif  // _LIBCPP__HASH_TABLE
2928